VirtualBox

source: vbox/trunk/src/VBox/HostDrivers/Support/SUPR3HardenedMain.cpp@ 66547

Last change on this file since 66547 was 66547, checked in by vboxsync, 8 years ago

Support: Close the handle to the support driver before forking

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 94.6 KB
Line 
1/* $Id: SUPR3HardenedMain.cpp 66547 2017-04-13 08:15:37Z vboxsync $ */
2/** @file
3 * VirtualBox Support Library - Hardened main().
4 */
5
6/*
7 * Copyright (C) 2006-2016 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.215389.xyz. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 *
17 * The contents of this file may alternatively be used under the terms
18 * of the Common Development and Distribution License Version 1.0
19 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20 * VirtualBox OSE distribution, in which case the provisions of the
21 * CDDL are applicable instead of those of the GPL.
22 *
23 * You may elect to license modified versions of this file under the
24 * terms and conditions of either the GPL or the CDDL or both.
25 */
26
27/** @page pg_hardening %VirtualBox %VM Process Hardening
28 *
29 * The %VM process hardening is to prevent malicious software from using
30 * %VirtualBox as a vehicle to obtain kernel level access.
31 *
32 * The %VirtualBox %VMM requires supervisor (kernel) level access to the CPU.
33 * For both practical and historical reasons, part of the %VMM is realized in
34 * ring-3, with a rich interface to the kernel part. While the device
35 * emulations can be executed exclusively in ring-3, we have performance
36 * optimizations that loads device emulation code into ring-0 and our special
37 * raw-mode execution context (none VT-x/AMD-V mode) for handling frequent
38 * operations a lot more efficiently. These share data between all three
39 * context (ring-3, ring-0 and raw-mode). All this poses a rather broad attack
40 * surface, which the hardening protects.
41 *
42 * The hardening focuses primarily on restricting access to the support driver,
43 * VBoxDrv or vboxdrv depending on the OS, as it is ultimately the link and
44 * instigator of the communication between ring-3 and the ring-0 and raw-mode
45 * contexts. A secondary focus is to make sure malicious code cannot be loaded
46 * and executed in the %VM process. Exactly how we go about this depends a lot
47 * on the host OS.
48 *
49 * @section sec_hardening_supdrv The Support Driver Interfaces
50 *
51 * The support driver has several interfaces thru which it can be accessed:
52 * - /dev/vboxdrv (win: \\Device\\VBoxDrv) for full unrestricted access.
53 * Offers a rich I/O control interface, which needs protecting.
54 * - /dev/vboxdrvu (win: \\Device\\VBoxDrvU) for restricted access, which
55 * VBoxSVC uses to query VT-x and AMD-V capabilities. This does not
56 * require protecting, though we limit it to the vboxgroup on some
57 * systems.
58 * - \\Device\\VBoxDrvStub on Windows for protecting the second stub
59 * process and its child, the %VM process. This is an open+close
60 * interface, only available to partially verified stub processes.
61 * - \\Device\\VBoxDrvErrorInfo on Windows for obtaining detailed error
62 * information on a previous attempt to open \\Device\\VBoxDrv or
63 * \\Device\\VBoxDrvStub. Open, read and close only interface.
64 *
65 * The rest of VBox accesses the device interface thru the support library,
66 * @ref grp_sup "SUPR3" / sup.h.
67 *
68 * The support driver also exposes a set of functions and data that other VBox
69 * ring-0 modules can import from. This includes much of the IPRT we need in
70 * the ring-0 part of the %VMM and device emulations.
71 *
72 * The ring-0 part of the %VMM and device emulations are loaded via the
73 * #SUPR3LoadModule and #SUPR3LoadServiceModule support library function, which
74 * both translates to a sequence of I/O controls against /dev/vboxdrv. On
75 * Windows we use the native kernel loader to load the module, while on the
76 * other systems ring-3 prepares the bits with help from the IPRT loader code.
77 *
78 *
79 * @section sec_hardening_unix Hardening on UNIX-like OSes
80 *
81 * On UNIX-like systems (Solaris, Linux, darwin, freebsd, ...) we put our trust
82 * in root and that root knows what he/she/it is doing.
83 *
84 * We only allow root to get full unrestricted access to the support driver.
85 * The device node corresponding to unrestricted access (/dev/vboxdrv) is own by
86 * root and has a 0600 access mode (i.e. only accessible to the owner, root). In
87 * addition to this file system level restriction, the support driver also
88 * checks that the effective user ID (EUID) is root when it is being opened.
89 *
90 * The %VM processes temporarily assume root privileges using the set-uid-bit on
91 * the executable with root as owner. In fact, all the files and directories we
92 * install are owned by root and the wheel (or equivalent gid = 0) group,
93 * including extension pack files.
94 *
95 * The executable with the set-uid-to-root-bit set is a stub binary that has no
96 * unnecessary library dependencies (only libc, pthreads, dynamic linker) and
97 * simply calls #SUPR3HardenedMain. It does the following:
98 * 1. Validate the VirtualBox installation (#supR3HardenedVerifyAll):
99 * - Check that the executable file of the process is one of the known
100 * VirtualBox executables.
101 * - Check that all mandatory files are present.
102 * - Check that all installed files and directories (both optional and
103 * mandatory ones) are owned by root:wheel and are not writable by
104 * anyone except root.
105 * - Check that all the parent directories, all the way up to the root
106 * if possible, only permits root (or system admin) to change them.
107 * This is that to rule out unintentional rename races.
108 * - On some systems we may also validate the cryptographic signtures
109 * of executable images.
110 *
111 * 2. Open a file descriptor for the support device driver
112 * (#supR3HardenedMainOpenDevice).
113 *
114 * 3. Grab ICMP capabilities for NAT ping support, if required by the OS
115 * (#supR3HardenedMainGrabCapabilites).
116 *
117 * 4. Correctly drop the root privileges
118 * (#supR3HardenedMainDropPrivileges).
119 *
120 * 5. Load the VBoxRT dynamic link library and hand over the file
121 * descriptor to the support library code in it
122 * (#supR3HardenedMainInitRuntime).
123 *
124 * 6. Load the dynamic library containing the actual %VM front end code and
125 * run it (tail of #SUPR3HardenedMain).
126 *
127 * The set-uid-to-root stub executable is paired with a dynamic link library
128 * which export one TrustedMain entry point (see #FNSUPTRUSTEDMAIN) that we
129 * call. In case of error reporting, the library may also export a TrustedError
130 * function (#FNSUPTRUSTEDERROR).
131 *
132 * That the set-uid-to-root-bit modifies the dynamic linker behavior on all
133 * systems, even after we've dropped back to the real user ID, is something we
134 * take advantage of. The dynamic linkers takes special care to prevent users
135 * from using clever tricks to inject their own code into set-uid processes and
136 * causing privilege escalation issues. This is the exact help we need.
137 *
138 * The VirtualBox installation location is hardcoded, which means the any
139 * dynamic linker paths embedded or inferred from the executable and dynamic
140 * libraries are also hardcoded. This helps eliminating search path attack
141 * vectors at the cost of being inflexible regarding installation location.
142 *
143 * In addition to what the dynamic linker does for us, the VirtualBox code will
144 * not directly be calling either RTLdrLoad or dlopen to load dynamic link
145 * libraries into the process. Instead it will call #SUPR3HardenedLdrLoad,
146 * #SUPR3HardenedLdrLoadAppPriv and #SUPR3HardenedLdrLoadPlugIn to do the
147 * loading. These functions will perform the same validations on the file being
148 * loaded as #SUPR3HardenedMain did in its validation step. So, anything we
149 * load must be installed with root/wheel as owner/group, the directory we load
150 * it from must also be owned by root:wheel and now allow for renaming the file.
151 * Similar ownership restrictions applies to all the parent directories (except
152 * on darwin).
153 *
154 * So, we place the responsibility of not installing malicious software on the
155 * root user on UNIX-like systems. Which is fair enough, in our opinion.
156 *
157 *
158 * @section sec_hardening_win Hardening on Windows
159 *
160 * On Windows we cannot put the same level or trust in the Administrator user(s)
161 * (equivalent of root/wheel on unix) as on the UNIX-like systems, which
162 * complicates things greatly.
163 *
164 * Some of the blame for this can be given to Windows being a descendant /
165 * replacement for a set of single user systems: DOS, Windows 1.0-3.11 Windows
166 * 95-ME, and OS/2. Users of NT 3.1 and later was inclined to want to always
167 * run it with full root/administrator privileges like they had done on the
168 * predecessors, while Microsoft didn't provide much incentive for more secure
169 * alternatives. Bad idea, security wise, but execellent for the security
170 * software industry. For this reason using a set-uid-to-root approach is
171 * pointless, even if Windows had one.
172 *
173 * So, in order to protect access to the support driver and protect the %VM
174 * process while it's running we have to do a lot more work. A keystone in the
175 * defences is cryptographic code signing. Here's the short version of what we
176 * do:
177 * - Minimal stub executable, signed with the same certificate as the
178 * kernel driver.
179 *
180 * - The stub executable respawns itself twice, hooking the NTDLL init
181 * routine to perform protection tasks as early as possible. The parent
182 * stub helps keep in the child clean for verification as does the
183 * support driver.
184 *
185 * - In order to protect against loading unwanted code into the process,
186 * the stub processes installs DLL load hooks with NTDLL as well as
187 * directly intercepting the LdrLoadDll and NtCreateSection APIs.
188 *
189 * - The support driver will verify all but the initial process very
190 * thoroughly before allowing them protection and in the final case full
191 * unrestricted access.
192 *
193 *
194 * @subsection sec_hardening_win_protsoft 3rd Party "Protection" Software
195 *
196 * What makes our life REALLY difficult on Windows is this 3rd party "security"
197 * software which is more or less required to keep a Windows system safe for
198 * normal users and all corporate IT departments rightly insists on installing.
199 * After the kernel patching clampdown in Vista, anti-* software has to do a
200 * lot more mucking about in user mode to get their job (kind of) done. So, it
201 * is common practice to patch a lot of NTDLL, KERNEL32, the executable import
202 * table, load extra DLLs into the process, allocate executable memory in the
203 * process (classic code injection) and more.
204 *
205 * The BIG problem with all this is that it is indistinguishable from what
206 * malicious software would be doing in order to intercept process activity
207 * (network sniffing, maybe password snooping) or gain a level of kernel access
208 * via the support driver. So, the "protection" software is what is currently
209 * forcing us to do the pre-NTDLL initialization.
210 *
211 *
212 * @subsection sec_hardening_win_1st_stub The Initial Stub Process
213 *
214 * We share the stub executable approach with the UNIX-like systems, so there's
215 * the #SUPR3HardenedMain calling stub executable with its partner DLL exporting
216 * TrustedMain and TrustedError. However, the stub executable does a lot more,
217 * while doing it in a more bare metal fashion:
218 * - It does not use the Microsoft CRT, what we need of CRT functions comes
219 * from IPRT.
220 * - It does not statically import anything. This is to avoid having an
221 * import table that can be patched to intercept our calls or extended to
222 * load additional DLLs.
223 * - Direct NT system calls. System calls normally going thru NTDLL, but
224 * since there is so much software out there which wants to patch known
225 * NTDLL entry points to control our software (either for good or
226 * malicious reasons), we do it ourselves.
227 *
228 * The initial stub process is not really to be trusted, though we try our best
229 * to limit potential harm (user mode debugger checks, disable thread creation).
230 * So, when it enters #SUPR3HardenedMain we only call #supR3HardenedVerifyAll to
231 * verify the installation (known executables and DLLs, checking their code
232 * signing signatures, keeping them all open to deny deletion and replacing) and
233 * does a respawn via #supR3HardenedWinReSpawn.
234 *
235 *
236 * @subsection sec_hardening_win_2nd_stub The Second Stub Process
237 *
238 * The second stub process will be created in suspended state, i.e. the main
239 * thread is suspended before it executes a single instruction. It is also
240 * created with a less generous ACLs, though this doesn't protect us from admin
241 * users. In order for #SUPR3HardenedMain to figure that it is the second stub
242 * process, the zeroth command line argument has been replaced by a known magic
243 * string (UUID).
244 *
245 * Now, before the process starts executing, the parent (initial stub) will
246 * patch the LdrInitializeThunk entry point in NTDLL to call
247 * #supR3HardenedEarlyProcessInit via #supR3HardenedEarlyProcessInitThunk. The
248 * parent will also plant some synchronization stuff via #g_ProcParams (NTDLL
249 * location, inherited event handles and associated ping-pong equipment).
250 *
251 * The LdrInitializeThunk entry point of NTDLL is where the kernel sets up
252 * process execution to start executing (via a user alert, so it is not subject
253 * to SetThreadContext). LdrInitializeThunk performs process, NTDLL and
254 * sub-system client (kernel32) initialization. A lot of "protection" software
255 * uses triggers in this initialization sequence (like the KERNEL32.DLL load
256 * event), so we avoid quite a bit of problems by getting our stuff done early
257 * on.
258 *
259 * However, there are also those that uses events that triggers immediately when
260 * the process is created or/and starts executing the first instruction. But we
261 * can easily counter these as we have a known process state we can restore. So,
262 * the first thing that #supR3HardenedEarlyProcessInit does is to signal the
263 * parent to perform a child purification, so the potentially evil influences
264 * can be exorcised.
265 *
266 * What the parent does during the purification is very similar to what the
267 * kernel driver will do later on when verifying the second stub and the %VM
268 * processes, except that instead of failing when encountering an shortcoming it
269 * will take corrective actions:
270 * - Executable memory regions not belonging to a DLL mapping will be
271 * attempted freed, and we'll only fail if we can't evict them.
272 * - All pages in the executable images in the process (should be just the
273 * stub executable and NTDLL) will be compared to the pristine fixed-up
274 * copy prepared by the IPRT PE loader code, restoring any bytes which
275 * appears differently in the child. (#g_ProcParams is exempted,
276 * LdrInitializeThunk is set to call NtTerminateThread.)
277 * - Unwanted DLLs will be unloaded (we have a set of DLLs we like).
278 *
279 * Before signalling the second stub process that it has been purified and should
280 * get on with it, the parent will close all handles with unrestricted access to
281 * the process and thread so that the initial stub process no longer can
282 * influence the child in any really harmful way. (The caller of CreateProcess
283 * usually receives handles with unrestricted access to the child process and
284 * its main thread. These could in theory be used with DuplicateHandle or
285 * WriteProcessMemory to get at the %VM process if we're not careful.)
286 *
287 * #supR3HardenedEarlyProcessInit will continue with opening the log file
288 * (requires command line parsing). It will continue to initialize a bunch of
289 * global variables, system calls and trustworthy/harmless NTDLL imports.
290 * #supR3HardenedWinInit is then called to setup image verification, that is:
291 * - Hook the NtCreateSection entry point in NTDLL so we can check all
292 * executable mappings before they're created and can be mapped. The
293 * NtCreateSection code jumps to #supR3HardenedMonitor_NtCreateSection.
294 * - Hook (ditto) the LdrLoadDll entry point in NTDLL so we can
295 * pre-validate all images that gets loaded the normal way (partly
296 * because the NtCreateSection context is restrictive because the NTDLL
297 * loader lock is usually held, which prevents us from safely calling
298 * WinVerityTrust). The LdrLoadDll code jumps to
299 * #supR3HardenedMonitor_LdrLoadDll.
300 *
301 * The image/DLL verification hooks are at this point able to verify DLLs
302 * containing embedded code signing signatures, and will restrict the locations
303 * from which DLLs will be loaded. When #SUPR3HardenedMain gets going later on,
304 * they will start insisting on everything having valid signatures, either
305 * embedded or in a signed installer catalog file.
306 *
307 * The function also irrevocably disables debug notifications related to the
308 * current thread, just to make attaching a debugging that much more difficult
309 * and less useful.
310 *
311 * Now, the second stub process will open the so called stub device
312 * (\\Device\\VBoxDrvStub), that is a special support driver device node that
313 * tells the support driver to:
314 * - Protect the process against the OpenProcess and OpenThread attack
315 * vectors by stripping risky access rights.
316 * - Check that the process isn't being debugged.
317 * - Check that the process contains exactly one thread.
318 * - Check that the process doesn't have any unknown DLLs loaded into it.
319 * - Check that the process doesn't have any executable memory (other than
320 * DLL sections) in it.
321 * - Check that the process executable is a known VBox executable which may
322 * access the support driver.
323 * - Check that the process executable is signed with the same code signing
324 * certificate as the driver and that the on disk image is valid
325 * according to its embedded signature.
326 * - Check all the signature of all DLLs in the process (NTDLL) if they are
327 * signed, and only accept unsigned ones in versions where they are known
328 * not to be signed.
329 * - Check that the code and readonly parts of the executable and DLLs
330 * mapped into the process matches the on disk content (no patches other
331 * than our own two in NTDLL are allowed).
332 *
333 * Once granted access to the stub device, #supR3HardenedEarlyProcessInit will
334 * restore the LdrInitializeThunk code and let the process perform normal
335 * initialization. Leading us to #SUPR3HardenedMain where we detect that this
336 * is the 2nd stub process and does another respawn.
337 *
338 *
339 * @subsection sec_hardening_win_3rd_stub The Final Stub / VM Process
340 *
341 * The third stub process is what becomes the %VM process. Because the parent
342 * has opened \\Device\\VBoxDrvSub, it is protected from malicious OpenProcess &
343 * OpenThread calls from the moment of inception, practically speaking.
344 *
345 * It goes thru the same suspended creation, patching, purification and such as
346 * its parent (the second stub process). However, instead of opening
347 * \\Device\\VBoxDrvStub from #supR3HardenedEarlyProcessInit, it opens the
348 * support driver for full unrestricted access, i.e. \\Device\\VBoxDrv.
349 *
350 * The support driver will perform the same checks as it did when
351 * \\Device\\VBoxDrvStub was opened, but in addition it will:
352 * - Check that the process is the first child of a process that opened
353 * \\Device\\VBoxDrvStub.
354 * - Check that the parent process is still alive.
355 * - Scan all open handles in the system for potentially harmful ones to
356 * the process or the primary thread.
357 *
358 * Knowing that the process is genuinly signed with the same certificate as the
359 * kernel driver, and the exectuable code in the process is either shipped by us
360 * or Microsoft, the support driver will trust it with full access and to keep
361 * the handle secure.
362 *
363 * We also trust the protection the support driver gives the process to keep out
364 * malicious ring-3 code, and therefore any code, patching or other mysterious
365 * stuff that enteres the process must be from kernel mode and that we can trust
366 * it (the alternative interpretation is that the kernel has been breanched
367 * already, which isn't our responsibility). This means that, the anti-software
368 * products can do whatever they like from this point on. However, should they
369 * do unrevertable changes to the process before this point, VirtualBox won't
370 * work.
371 *
372 * As in the second stub process, we'll now do normal process initialization and
373 * #SUPR3HardenedMain will take control. It will detect that it is being called
374 * by the 3rd stub process because of a different magic string starting the
375 * command line, and not respawn itself any more. #SUPR3HardenedMain will
376 * recheck the VirtualBox installation, keeping all known files open just like
377 * in two previous stub processes.
378 *
379 * It will then load the Windows cryptographic API and load the trusted root
380 * certificates from the Windows store. The API enables using installation
381 * catalog files for signature checking as well as providing a second
382 * verification in addition to our own implementation (IPRT). The certificates
383 * allows our signature validation implementation to validate all embedded
384 * signatures, not just the microsoft ones and the one signed by our own
385 * certificate.
386 *
387 */
388
389
390/*********************************************************************************************************************************
391* Header Files *
392*********************************************************************************************************************************/
393#if defined(RT_OS_OS2)
394# define INCL_BASE
395# define INCL_ERRORS
396# include <os2.h>
397# include <stdio.h>
398# include <stdlib.h>
399# include <dlfcn.h>
400# include <unistd.h>
401
402#elif RT_OS_WINDOWS
403# include <iprt/nt/nt-and-windows.h>
404
405#else /* UNIXes */
406# ifdef RT_OS_DARWIN
407# define _POSIX_C_SOURCE 1 /* pick the correct prototype for unsetenv. */
408# endif
409# include <iprt/types.h> /* stdint fun on darwin. */
410
411# include <stdio.h>
412# include <stdlib.h>
413# include <dlfcn.h>
414# include <limits.h>
415# include <errno.h>
416# include <unistd.h>
417# include <sys/stat.h>
418# include <sys/time.h>
419# include <sys/types.h>
420# if defined(RT_OS_LINUX)
421# undef USE_LIB_PCAP /* don't depend on libcap as we had to depend on either
422 libcap1 or libcap2 */
423
424# undef _POSIX_SOURCE
425# include <linux/types.h> /* sys/capabilities from uek-headers require this */
426# include <sys/capability.h>
427# include <sys/prctl.h>
428# ifndef CAP_TO_MASK
429# define CAP_TO_MASK(cap) RT_BIT(cap)
430# endif
431# elif defined(RT_OS_FREEBSD)
432# include <sys/param.h>
433# include <sys/sysctl.h>
434# elif defined(RT_OS_SOLARIS)
435# include <priv.h>
436# endif
437# include <pwd.h>
438# ifdef RT_OS_DARWIN
439# include <mach-o/dyld.h>
440# endif
441
442#endif
443
444#include <VBox/sup.h>
445#include <VBox/err.h>
446#ifdef RT_OS_WINDOWS
447# include <VBox/version.h>
448#endif
449#include <iprt/ctype.h>
450#include <iprt/string.h>
451#include <iprt/initterm.h>
452#include <iprt/param.h>
453
454#include "SUPLibInternal.h"
455
456
457/*********************************************************************************************************************************
458* Defined Constants And Macros *
459*********************************************************************************************************************************/
460/** @def SUP_HARDENED_SUID
461 * Whether we're employing set-user-ID-on-execute in the hardening.
462 */
463#if !defined(RT_OS_OS2) && !defined(RT_OS_WINDOWS) && !defined(RT_OS_L4)
464# define SUP_HARDENED_SUID
465#else
466# undef SUP_HARDENED_SUID
467#endif
468
469/** @def SUP_HARDENED_SYM
470 * Decorate a symbol that's resolved dynamically.
471 */
472#ifdef RT_OS_OS2
473# define SUP_HARDENED_SYM(sym) "_" sym
474#else
475# define SUP_HARDENED_SYM(sym) sym
476#endif
477
478
479/*********************************************************************************************************************************
480* Structures and Typedefs *
481*********************************************************************************************************************************/
482/** @see RTR3InitEx */
483typedef DECLCALLBACK(int) FNRTR3INITEX(uint32_t iVersion, uint32_t fFlags, int cArgs,
484 char **papszArgs, const char *pszProgramPath);
485typedef FNRTR3INITEX *PFNRTR3INITEX;
486
487/** @see RTLogRelPrintf */
488typedef DECLCALLBACK(void) FNRTLOGRELPRINTF(const char *pszFormat, ...);
489typedef FNRTLOGRELPRINTF *PFNRTLOGRELPRINTF;
490
491
492/**
493 * Descriptor of an environment variable to purge.
494 */
495typedef struct SUPENVPURGEDESC
496{
497 /** Name of the environment variable to purge. */
498 const char *pszEnv;
499 /** The length of the variable name. */
500 uint8_t cchEnv;
501 /** Flag whether a failure in purging the variable leads to
502 * a fatal error resulting in an process exit. */
503 bool fPurgeErrFatal;
504} SUPENVPURGEDESC;
505/** Pointer to a environment variable purge descriptor. */
506typedef SUPENVPURGEDESC *PSUPENVPURGEDESC;
507/** Pointer to a const environment variable purge descriptor. */
508typedef const SUPENVPURGEDESC *PCSUPENVPURGEDESC;
509
510/**
511 * Descriptor of an command line argument to purge.
512 */
513typedef struct SUPARGPURGEDESC
514{
515 /** Name of the argument to purge. */
516 const char *pszArg;
517 /** The length of the argument name. */
518 uint8_t cchArg;
519 /** Flag whether the argument is followed by an extra argument
520 * which must be purged too */
521 bool fTakesValue;
522} SUPARGPURGEDESC;
523/** Pointer to a environment variable purge descriptor. */
524typedef SUPARGPURGEDESC *PSUPARGPURGEDESC;
525/** Pointer to a const environment variable purge descriptor. */
526typedef const SUPARGPURGEDESC *PCSUPARGPURGEDESC;
527
528
529/*********************************************************************************************************************************
530* Global Variables *
531*********************************************************************************************************************************/
532/** The pre-init data we pass on to SUPR3 (residing in VBoxRT). */
533static SUPPREINITDATA g_SupPreInitData;
534/** The program executable path. */
535#ifndef RT_OS_WINDOWS
536static
537#endif
538char g_szSupLibHardenedExePath[RTPATH_MAX];
539/** The application bin directory path. */
540static char g_szSupLibHardenedAppBinPath[RTPATH_MAX];
541
542/** The program name. */
543static const char *g_pszSupLibHardenedProgName;
544/** The flags passed to SUPR3HardenedMain. */
545static uint32_t g_fSupHardenedMain;
546
547#ifdef SUP_HARDENED_SUID
548/** The real UID at startup. */
549static uid_t g_uid;
550/** The real GID at startup. */
551static gid_t g_gid;
552# ifdef RT_OS_LINUX
553static uint32_t g_uCaps;
554static uint32_t g_uCapsVersion;
555# endif
556#endif
557
558/** The startup log file. */
559#ifdef RT_OS_WINDOWS
560static HANDLE g_hStartupLog = NULL;
561#else
562static int g_hStartupLog = -1;
563#endif
564/** The number of bytes we've written to the startup log. */
565static uint32_t volatile g_cbStartupLog = 0;
566
567/** The current SUPR3HardenedMain state / location. */
568SUPR3HARDENEDMAINSTATE g_enmSupR3HardenedMainState = SUPR3HARDENEDMAINSTATE_NOT_YET_CALLED;
569AssertCompileSize(g_enmSupR3HardenedMainState, sizeof(uint32_t));
570
571#ifdef RT_OS_WINDOWS
572/** Pointer to VBoxRT's RTLogRelPrintf function so we can write errors to the
573 * release log at runtime. */
574static PFNRTLOGRELPRINTF g_pfnRTLogRelPrintf = NULL;
575/** Log volume name (for attempting volume flush). */
576static RTUTF16 g_wszStartupLogVol[16];
577#endif
578
579/** Environment variables to purge from the process because
580 * they are known to be harmful. */
581static const SUPENVPURGEDESC g_aSupEnvPurgeDescs[] =
582{
583 /* pszEnv fPurgeErrFatal */
584 /* Qt related environment variables: */
585 { RT_STR_TUPLE("QT_QPA_PLATFORM_PLUGIN_PATH"), true },
586 { RT_STR_TUPLE("QT_PLUGIN_PATH"), true },
587 /* ALSA related environment variables: */
588 { RT_STR_TUPLE("ALSA_MIXER_SIMPLE_MODULES"), true },
589 { RT_STR_TUPLE("LADSPA_PATH"), true },
590};
591
592/** Arguments to purge from the argument vector because
593 * they are known to be harmful. */
594static const SUPARGPURGEDESC g_aSupArgPurgeDescs[] =
595{
596 /* pszArg fTakesValue */
597 /* Qt related environment variables: */
598 { RT_STR_TUPLE("-platformpluginpath"), true },
599};
600
601/*********************************************************************************************************************************
602* Internal Functions *
603*********************************************************************************************************************************/
604#ifdef SUP_HARDENED_SUID
605static void supR3HardenedMainDropPrivileges(void);
606#endif
607static PFNSUPTRUSTEDERROR supR3HardenedMainGetTrustedError(const char *pszProgName);
608
609
610/**
611 * Safely copy one or more strings into the given buffer.
612 *
613 * @returns VINF_SUCCESS or VERR_BUFFER_OVERFLOW.
614 * @param pszDst The destionation buffer.
615 * @param cbDst The size of the destination buffer.
616 * @param ... One or more zero terminated strings, ending with
617 * a NULL.
618 */
619static int suplibHardenedStrCopyEx(char *pszDst, size_t cbDst, ...)
620{
621 int rc = VINF_SUCCESS;
622
623 if (cbDst == 0)
624 return VERR_BUFFER_OVERFLOW;
625
626 va_list va;
627 va_start(va, cbDst);
628 for (;;)
629 {
630 const char *pszSrc = va_arg(va, const char *);
631 if (!pszSrc)
632 break;
633
634 size_t cchSrc = suplibHardenedStrLen(pszSrc);
635 if (cchSrc < cbDst)
636 {
637 suplibHardenedMemCopy(pszDst, pszSrc, cchSrc);
638 pszDst += cchSrc;
639 cbDst -= cchSrc;
640 }
641 else
642 {
643 rc = VERR_BUFFER_OVERFLOW;
644 if (cbDst > 1)
645 {
646 suplibHardenedMemCopy(pszDst, pszSrc, cbDst - 1);
647 pszDst += cbDst - 1;
648 cbDst = 1;
649 }
650 }
651 *pszDst = '\0';
652 }
653 va_end(va);
654
655 return rc;
656}
657
658
659/**
660 * Exit current process in the quickest possible fashion.
661 *
662 * @param rcExit The exit code.
663 */
664DECLNORETURN(void) suplibHardenedExit(RTEXITCODE rcExit)
665{
666 for (;;)
667 {
668#ifdef RT_OS_WINDOWS
669 if (g_enmSupR3HardenedMainState >= SUPR3HARDENEDMAINSTATE_WIN_IMPORTS_RESOLVED)
670 ExitProcess(rcExit);
671 if (RtlExitUserProcess != NULL)
672 RtlExitUserProcess(rcExit);
673 NtTerminateProcess(NtCurrentProcess(), rcExit);
674#else
675 _Exit(rcExit);
676#endif
677 }
678}
679
680
681/**
682 * Writes a substring to standard error.
683 *
684 * @param pch The start of the substring.
685 * @param cch The length of the substring.
686 */
687static void suplibHardenedPrintStrN(const char *pch, size_t cch)
688{
689#ifdef RT_OS_WINDOWS
690 HANDLE hStdOut = NtCurrentPeb()->ProcessParameters->StandardOutput;
691 if (hStdOut != NULL)
692 {
693 if (g_enmSupR3HardenedMainState >= SUPR3HARDENEDMAINSTATE_WIN_IMPORTS_RESOLVED)
694 {
695 DWORD cbWritten;
696 WriteFile(hStdOut, pch, (DWORD)cch, &cbWritten, NULL);
697 }
698 /* Windows 7 and earlier uses fake handles, with the last two bits set ((hStdOut & 3) == 3). */
699 else if (NtWriteFile != NULL && ((uintptr_t)hStdOut & 3) == 0)
700 {
701 IO_STATUS_BLOCK Ios = RTNT_IO_STATUS_BLOCK_INITIALIZER;
702 NtWriteFile(hStdOut, NULL /*Event*/, NULL /*ApcRoutine*/, NULL /*ApcContext*/,
703 &Ios, (PVOID)pch, (ULONG)cch, NULL /*ByteOffset*/, NULL /*Key*/);
704 }
705 }
706#else
707 int res = write(2, pch, cch);
708 NOREF(res);
709#endif
710}
711
712
713/**
714 * Writes a string to standard error.
715 *
716 * @param psz The string.
717 */
718static void suplibHardenedPrintStr(const char *psz)
719{
720 suplibHardenedPrintStrN(psz, suplibHardenedStrLen(psz));
721}
722
723
724/**
725 * Writes a char to standard error.
726 *
727 * @param ch The character value to write.
728 */
729static void suplibHardenedPrintChr(char ch)
730{
731 suplibHardenedPrintStrN(&ch, 1);
732}
733
734#ifndef IPRT_NO_CRT
735
736/**
737 * Writes a decimal number to stdard error.
738 *
739 * @param uValue The value.
740 */
741static void suplibHardenedPrintDecimal(uint64_t uValue)
742{
743 char szBuf[64];
744 char *pszEnd = &szBuf[sizeof(szBuf) - 1];
745 char *psz = pszEnd;
746
747 *psz-- = '\0';
748
749 do
750 {
751 *psz-- = '0' + (uValue % 10);
752 uValue /= 10;
753 } while (uValue > 0);
754
755 psz++;
756 suplibHardenedPrintStrN(psz, pszEnd - psz);
757}
758
759
760/**
761 * Writes a hexadecimal or octal number to standard error.
762 *
763 * @param uValue The value.
764 * @param uBase The base (16 or 8).
765 * @param fFlags Format flags.
766 */
767static void suplibHardenedPrintHexOctal(uint64_t uValue, unsigned uBase, uint32_t fFlags)
768{
769 static char const s_achDigitsLower[17] = "0123456789abcdef";
770 static char const s_achDigitsUpper[17] = "0123456789ABCDEF";
771 const char *pchDigits = !(fFlags & RTSTR_F_CAPITAL) ? s_achDigitsLower : s_achDigitsUpper;
772 unsigned cShift = uBase == 16 ? 4 : 3;
773 unsigned fDigitMask = uBase == 16 ? 0xf : 7;
774 char szBuf[64];
775 char *pszEnd = &szBuf[sizeof(szBuf) - 1];
776 char *psz = pszEnd;
777
778 *psz-- = '\0';
779
780 do
781 {
782 *psz-- = pchDigits[uValue & fDigitMask];
783 uValue >>= cShift;
784 } while (uValue > 0);
785
786 if ((fFlags & RTSTR_F_SPECIAL) && uBase == 16)
787 {
788 *psz-- = !(fFlags & RTSTR_F_CAPITAL) ? 'x' : 'X';
789 *psz-- = '0';
790 }
791
792 psz++;
793 suplibHardenedPrintStrN(psz, pszEnd - psz);
794}
795
796
797/**
798 * Writes a wide character string to standard error.
799 *
800 * @param pwsz The string.
801 */
802static void suplibHardenedPrintWideStr(PCRTUTF16 pwsz)
803{
804 for (;;)
805 {
806 RTUTF16 wc = *pwsz++;
807 if (!wc)
808 return;
809 if ( (wc < 0x7f && wc >= 0x20)
810 || wc == '\n'
811 || wc == '\r')
812 suplibHardenedPrintChr((char)wc);
813 else
814 {
815 suplibHardenedPrintStrN(RT_STR_TUPLE("\\x"));
816 suplibHardenedPrintHexOctal(wc, 16, 0);
817 }
818 }
819}
820
821#else /* IPRT_NO_CRT */
822
823/** Buffer structure used by suplibHardenedOutput. */
824struct SUPLIBHARDENEDOUTPUTBUF
825{
826 size_t off;
827 char szBuf[2048];
828};
829
830/** Callback for RTStrFormatV, see FNRTSTROUTPUT. */
831static DECLCALLBACK(size_t) suplibHardenedOutput(void *pvArg, const char *pachChars, size_t cbChars)
832{
833 SUPLIBHARDENEDOUTPUTBUF *pBuf = (SUPLIBHARDENEDOUTPUTBUF *)pvArg;
834 size_t cbTodo = cbChars;
835 for (;;)
836 {
837 size_t cbSpace = sizeof(pBuf->szBuf) - pBuf->off - 1;
838
839 /* Flush the buffer? */
840 if ( cbSpace == 0
841 || (cbTodo == 0 && pBuf->off))
842 {
843 suplibHardenedPrintStrN(pBuf->szBuf, pBuf->off);
844# ifdef RT_OS_WINDOWS
845 if (g_enmSupR3HardenedMainState >= SUPR3HARDENEDMAINSTATE_WIN_IMPORTS_RESOLVED)
846 OutputDebugString(pBuf->szBuf);
847# endif
848 pBuf->off = 0;
849 cbSpace = sizeof(pBuf->szBuf) - 1;
850 }
851
852 /* Copy the string into the buffer. */
853 if (cbTodo == 1)
854 {
855 pBuf->szBuf[pBuf->off++] = *pachChars;
856 break;
857 }
858 if (cbSpace >= cbTodo)
859 {
860 memcpy(&pBuf->szBuf[pBuf->off], pachChars, cbTodo);
861 pBuf->off += cbTodo;
862 break;
863 }
864 memcpy(&pBuf->szBuf[pBuf->off], pachChars, cbSpace);
865 pBuf->off += cbSpace;
866 cbTodo -= cbSpace;
867 }
868 pBuf->szBuf[pBuf->off] = '\0';
869
870 return cbChars;
871}
872
873#endif /* IPRT_NO_CRT */
874
875/**
876 * Simple printf to standard error.
877 *
878 * @param pszFormat The format string.
879 * @param va Arguments to format.
880 */
881DECLHIDDEN(void) suplibHardenedPrintFV(const char *pszFormat, va_list va)
882{
883#ifdef IPRT_NO_CRT
884 /*
885 * Use buffered output here to avoid character mixing on the windows
886 * console and to enable us to use OutputDebugString.
887 */
888 SUPLIBHARDENEDOUTPUTBUF Buf;
889 Buf.off = 0;
890 Buf.szBuf[0] = '\0';
891 RTStrFormatV(suplibHardenedOutput, &Buf, NULL, NULL, pszFormat, va);
892
893#else /* !IPRT_NO_CRT */
894 /*
895 * Format loop.
896 */
897 char ch;
898 const char *pszLast = pszFormat;
899 for (;;)
900 {
901 ch = *pszFormat;
902 if (!ch)
903 break;
904 pszFormat++;
905
906 if (ch == '%')
907 {
908 /*
909 * Format argument.
910 */
911
912 /* Flush unwritten bits. */
913 if (pszLast != pszFormat - 1)
914 suplibHardenedPrintStrN(pszLast, pszFormat - pszLast - 1);
915 pszLast = pszFormat;
916 ch = *pszFormat++;
917
918 /* flags. */
919 uint32_t fFlags = 0;
920 for (;;)
921 {
922 if (ch == '#') fFlags |= RTSTR_F_SPECIAL;
923 else if (ch == '-') fFlags |= RTSTR_F_LEFT;
924 else if (ch == '+') fFlags |= RTSTR_F_PLUS;
925 else if (ch == ' ') fFlags |= RTSTR_F_BLANK;
926 else if (ch == '0') fFlags |= RTSTR_F_ZEROPAD;
927 else if (ch == '\'') fFlags |= RTSTR_F_THOUSAND_SEP;
928 else break;
929 ch = *pszFormat++;
930 }
931
932 /* Width and precision - ignored. */
933 while (RT_C_IS_DIGIT(ch))
934 ch = *pszFormat++;
935 if (ch == '*')
936 va_arg(va, int);
937 if (ch == '.')
938 {
939 do ch = *pszFormat++;
940 while (RT_C_IS_DIGIT(ch));
941 if (ch == '*')
942 va_arg(va, int);
943 }
944
945 /* Size. */
946 char chArgSize = 0;
947 switch (ch)
948 {
949 case 'z':
950 case 'L':
951 case 'j':
952 case 't':
953 chArgSize = ch;
954 ch = *pszFormat++;
955 break;
956
957 case 'l':
958 chArgSize = ch;
959 ch = *pszFormat++;
960 if (ch == 'l')
961 {
962 chArgSize = 'L';
963 ch = *pszFormat++;
964 }
965 break;
966
967 case 'h':
968 chArgSize = ch;
969 ch = *pszFormat++;
970 if (ch == 'h')
971 {
972 chArgSize = 'H';
973 ch = *pszFormat++;
974 }
975 break;
976 }
977
978 /*
979 * Do type specific formatting.
980 */
981 switch (ch)
982 {
983 case 'c':
984 ch = (char)va_arg(va, int);
985 suplibHardenedPrintChr(ch);
986 break;
987
988 case 's':
989 if (chArgSize == 'l')
990 {
991 PCRTUTF16 pwszStr = va_arg(va, PCRTUTF16 );
992 if (RT_VALID_PTR(pwszStr))
993 suplibHardenedPrintWideStr(pwszStr);
994 else
995 suplibHardenedPrintStr("<NULL>");
996 }
997 else
998 {
999 const char *pszStr = va_arg(va, const char *);
1000 if (!RT_VALID_PTR(pszStr))
1001 pszStr = "<NULL>";
1002 suplibHardenedPrintStr(pszStr);
1003 }
1004 break;
1005
1006 case 'd':
1007 case 'i':
1008 {
1009 int64_t iValue;
1010 if (chArgSize == 'L' || chArgSize == 'j')
1011 iValue = va_arg(va, int64_t);
1012 else if (chArgSize == 'l')
1013 iValue = va_arg(va, signed long);
1014 else if (chArgSize == 'z' || chArgSize == 't')
1015 iValue = va_arg(va, intptr_t);
1016 else
1017 iValue = va_arg(va, signed int);
1018 if (iValue < 0)
1019 {
1020 suplibHardenedPrintChr('-');
1021 iValue = -iValue;
1022 }
1023 suplibHardenedPrintDecimal(iValue);
1024 break;
1025 }
1026
1027 case 'p':
1028 case 'x':
1029 case 'X':
1030 case 'u':
1031 case 'o':
1032 {
1033 unsigned uBase = 10;
1034 uint64_t uValue;
1035
1036 switch (ch)
1037 {
1038 case 'p':
1039 fFlags |= RTSTR_F_ZEROPAD; /* Note not standard behaviour (but I like it this way!) */
1040 uBase = 16;
1041 break;
1042 case 'X':
1043 fFlags |= RTSTR_F_CAPITAL;
1044 case 'x':
1045 uBase = 16;
1046 break;
1047 case 'u':
1048 uBase = 10;
1049 break;
1050 case 'o':
1051 uBase = 8;
1052 break;
1053 }
1054
1055 if (ch == 'p' || chArgSize == 'z' || chArgSize == 't')
1056 uValue = va_arg(va, uintptr_t);
1057 else if (chArgSize == 'L' || chArgSize == 'j')
1058 uValue = va_arg(va, uint64_t);
1059 else if (chArgSize == 'l')
1060 uValue = va_arg(va, unsigned long);
1061 else
1062 uValue = va_arg(va, unsigned int);
1063
1064 if (uBase == 10)
1065 suplibHardenedPrintDecimal(uValue);
1066 else
1067 suplibHardenedPrintHexOctal(uValue, uBase, fFlags);
1068 break;
1069 }
1070
1071 case 'R':
1072 if (pszFormat[0] == 'r' && pszFormat[1] == 'c')
1073 {
1074 int iValue = va_arg(va, int);
1075 if (iValue < 0)
1076 {
1077 suplibHardenedPrintChr('-');
1078 iValue = -iValue;
1079 }
1080 suplibHardenedPrintDecimal(iValue);
1081 pszFormat += 2;
1082 break;
1083 }
1084 /* fall thru */
1085
1086 /*
1087 * Custom format.
1088 */
1089 default:
1090 suplibHardenedPrintStr("[bad format: ");
1091 suplibHardenedPrintStrN(pszLast, pszFormat - pszLast);
1092 suplibHardenedPrintChr(']');
1093 break;
1094 }
1095
1096 /* continue */
1097 pszLast = pszFormat;
1098 }
1099 }
1100
1101 /* Flush the last bits of the string. */
1102 if (pszLast != pszFormat)
1103 suplibHardenedPrintStrN(pszLast, pszFormat - pszLast);
1104#endif /* !IPRT_NO_CRT */
1105}
1106
1107
1108/**
1109 * Prints to standard error.
1110 *
1111 * @param pszFormat The format string.
1112 * @param ... Arguments to format.
1113 */
1114DECLHIDDEN(void) suplibHardenedPrintF(const char *pszFormat, ...)
1115{
1116 va_list va;
1117 va_start(va, pszFormat);
1118 suplibHardenedPrintFV(pszFormat, va);
1119 va_end(va);
1120}
1121
1122
1123/**
1124 * @copydoc RTPathStripFilename
1125 */
1126static void suplibHardenedPathStripFilename(char *pszPath)
1127{
1128 char *psz = pszPath;
1129 char *pszLastSep = pszPath;
1130
1131 for (;; psz++)
1132 {
1133 switch (*psz)
1134 {
1135 /* handle separators. */
1136#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
1137 case ':':
1138 pszLastSep = psz + 1;
1139 break;
1140
1141 case '\\':
1142#endif
1143 case '/':
1144 pszLastSep = psz;
1145 break;
1146
1147 /* the end */
1148 case '\0':
1149 if (pszLastSep == pszPath)
1150 *pszLastSep++ = '.';
1151 *pszLastSep = '\0';
1152 return;
1153 }
1154 }
1155 /* will never get here */
1156}
1157
1158
1159/**
1160 * @copydoc RTPathFilename
1161 */
1162DECLHIDDEN(char *) supR3HardenedPathFilename(const char *pszPath)
1163{
1164 const char *psz = pszPath;
1165 const char *pszLastComp = pszPath;
1166
1167 for (;; psz++)
1168 {
1169 switch (*psz)
1170 {
1171 /* handle separators. */
1172#if defined(RT_OS_WINDOWS) || defined(RT_OS_OS2)
1173 case ':':
1174 pszLastComp = psz + 1;
1175 break;
1176
1177 case '\\':
1178#endif
1179 case '/':
1180 pszLastComp = psz + 1;
1181 break;
1182
1183 /* the end */
1184 case '\0':
1185 if (*pszLastComp)
1186 return (char *)(void *)pszLastComp;
1187 return NULL;
1188 }
1189 }
1190
1191 /* will never get here */
1192}
1193
1194
1195/**
1196 * @copydoc RTPathAppPrivateNoArch
1197 */
1198DECLHIDDEN(int) supR3HardenedPathAppPrivateNoArch(char *pszPath, size_t cchPath)
1199{
1200#if !defined(RT_OS_WINDOWS) && defined(RTPATH_APP_PRIVATE)
1201 const char *pszSrcPath = RTPATH_APP_PRIVATE;
1202 size_t cchPathPrivateNoArch = suplibHardenedStrLen(pszSrcPath);
1203 if (cchPathPrivateNoArch >= cchPath)
1204 supR3HardenedFatal("supR3HardenedPathAppPrivateNoArch: Buffer overflow, %zu >= %zu\n", cchPathPrivateNoArch, cchPath);
1205 suplibHardenedMemCopy(pszPath, pszSrcPath, cchPathPrivateNoArch + 1);
1206 return VINF_SUCCESS;
1207
1208#else
1209 return supR3HardenedPathAppBin(pszPath, cchPath);
1210#endif
1211}
1212
1213
1214/**
1215 * @copydoc RTPathAppPrivateArch
1216 */
1217DECLHIDDEN(int) supR3HardenedPathAppPrivateArch(char *pszPath, size_t cchPath)
1218{
1219#if !defined(RT_OS_WINDOWS) && defined(RTPATH_APP_PRIVATE_ARCH)
1220 const char *pszSrcPath = RTPATH_APP_PRIVATE_ARCH;
1221 size_t cchPathPrivateArch = suplibHardenedStrLen(pszSrcPath);
1222 if (cchPathPrivateArch >= cchPath)
1223 supR3HardenedFatal("supR3HardenedPathAppPrivateArch: Buffer overflow, %zu >= %zu\n", cchPathPrivateArch, cchPath);
1224 suplibHardenedMemCopy(pszPath, pszSrcPath, cchPathPrivateArch + 1);
1225 return VINF_SUCCESS;
1226
1227#else
1228 return supR3HardenedPathAppBin(pszPath, cchPath);
1229#endif
1230}
1231
1232
1233/**
1234 * @copydoc RTPathSharedLibs
1235 */
1236DECLHIDDEN(int) supR3HardenedPathAppSharedLibs(char *pszPath, size_t cchPath)
1237{
1238#if !defined(RT_OS_WINDOWS) && defined(RTPATH_SHARED_LIBS)
1239 const char *pszSrcPath = RTPATH_SHARED_LIBS;
1240 size_t cchPathSharedLibs = suplibHardenedStrLen(pszSrcPath);
1241 if (cchPathSharedLibs >= cchPath)
1242 supR3HardenedFatal("supR3HardenedPathAppSharedLibs: Buffer overflow, %zu >= %zu\n", cchPathSharedLibs, cchPath);
1243 suplibHardenedMemCopy(pszPath, pszSrcPath, cchPathSharedLibs + 1);
1244 return VINF_SUCCESS;
1245
1246#else
1247 return supR3HardenedPathAppBin(pszPath, cchPath);
1248#endif
1249}
1250
1251
1252/**
1253 * @copydoc RTPathAppDocs
1254 */
1255DECLHIDDEN(int) supR3HardenedPathAppDocs(char *pszPath, size_t cchPath)
1256{
1257#if !defined(RT_OS_WINDOWS) && defined(RTPATH_APP_DOCS)
1258 const char *pszSrcPath = RTPATH_APP_DOCS;
1259 size_t cchPathAppDocs = suplibHardenedStrLen(pszSrcPath);
1260 if (cchPathAppDocs >= cchPath)
1261 supR3HardenedFatal("supR3HardenedPathAppDocs: Buffer overflow, %zu >= %zu\n", cchPathAppDocs, cchPath);
1262 suplibHardenedMemCopy(pszPath, pszSrcPath, cchPathAppDocs + 1);
1263 return VINF_SUCCESS;
1264
1265#else
1266 return supR3HardenedPathAppBin(pszPath, cchPath);
1267#endif
1268}
1269
1270
1271/**
1272 * Returns the full path to the executable in g_szSupLibHardenedExePath.
1273 *
1274 * @returns IPRT status code.
1275 */
1276static void supR3HardenedGetFullExePath(void)
1277{
1278 /*
1279 * Get the program filename.
1280 *
1281 * Most UNIXes have no API for obtaining the executable path, but provides a symbolic
1282 * link in the proc file system that tells who was exec'ed. The bad thing about this
1283 * is that we have to use readlink, one of the weirder UNIX APIs.
1284 *
1285 * Darwin, OS/2 and Windows all have proper APIs for getting the program file name.
1286 */
1287#if defined(RT_OS_LINUX) || defined(RT_OS_FREEBSD) || defined(RT_OS_SOLARIS)
1288# ifdef RT_OS_LINUX
1289 int cchLink = readlink("/proc/self/exe", &g_szSupLibHardenedExePath[0], sizeof(g_szSupLibHardenedExePath) - 1);
1290
1291# elif defined(RT_OS_SOLARIS)
1292 char szFileBuf[PATH_MAX + 1];
1293 sprintf(szFileBuf, "/proc/%ld/path/a.out", (long)getpid());
1294 int cchLink = readlink(szFileBuf, &g_szSupLibHardenedExePath[0], sizeof(g_szSupLibHardenedExePath) - 1);
1295
1296# else /* RT_OS_FREEBSD */
1297 int aiName[4];
1298 aiName[0] = CTL_KERN;
1299 aiName[1] = KERN_PROC;
1300 aiName[2] = KERN_PROC_PATHNAME;
1301 aiName[3] = getpid();
1302
1303 size_t cbPath = sizeof(g_szSupLibHardenedExePath);
1304 if (sysctl(aiName, RT_ELEMENTS(aiName), g_szSupLibHardenedExePath, &cbPath, NULL, 0) < 0)
1305 supR3HardenedFatal("supR3HardenedExecDir: sysctl failed\n");
1306 g_szSupLibHardenedExePath[sizeof(g_szSupLibHardenedExePath) - 1] = '\0';
1307 int cchLink = suplibHardenedStrLen(g_szSupLibHardenedExePath); /* paranoid? can't we use cbPath? */
1308
1309# endif
1310 if (cchLink < 0 || cchLink == sizeof(g_szSupLibHardenedExePath) - 1)
1311 supR3HardenedFatal("supR3HardenedExecDir: couldn't read \"%s\", errno=%d cchLink=%d\n",
1312 g_szSupLibHardenedExePath, errno, cchLink);
1313 g_szSupLibHardenedExePath[cchLink] = '\0';
1314
1315#elif defined(RT_OS_OS2) || defined(RT_OS_L4)
1316 _execname(g_szSupLibHardenedExePath, sizeof(g_szSupLibHardenedExePath));
1317
1318#elif defined(RT_OS_DARWIN)
1319 const char *pszImageName = _dyld_get_image_name(0);
1320 if (!pszImageName)
1321 supR3HardenedFatal("supR3HardenedExecDir: _dyld_get_image_name(0) failed\n");
1322 size_t cchImageName = suplibHardenedStrLen(pszImageName);
1323 if (!cchImageName || cchImageName >= sizeof(g_szSupLibHardenedExePath))
1324 supR3HardenedFatal("supR3HardenedExecDir: _dyld_get_image_name(0) failed, cchImageName=%d\n", cchImageName);
1325 suplibHardenedMemCopy(g_szSupLibHardenedExePath, pszImageName, cchImageName + 1);
1326
1327#elif defined(RT_OS_WINDOWS)
1328 char *pszDst = g_szSupLibHardenedExePath;
1329 int rc = RTUtf16ToUtf8Ex(g_wszSupLibHardenedExePath, RTSTR_MAX, &pszDst, sizeof(g_szSupLibHardenedExePath), NULL);
1330 if (RT_FAILURE(rc))
1331 supR3HardenedFatal("supR3HardenedExecDir: RTUtf16ToUtf8Ex failed, rc=%Rrc\n", rc);
1332#else
1333# error needs porting.
1334#endif
1335
1336 /*
1337 * Determine the application binary directory location.
1338 */
1339 suplibHardenedStrCopy(g_szSupLibHardenedAppBinPath, g_szSupLibHardenedExePath);
1340 suplibHardenedPathStripFilename(g_szSupLibHardenedAppBinPath);
1341
1342 if (g_enmSupR3HardenedMainState < SUPR3HARDENEDMAINSTATE_HARDENED_MAIN_CALLED)
1343 supR3HardenedFatal("supR3HardenedExecDir: Called before SUPR3HardenedMain! (%d)\n", g_enmSupR3HardenedMainState);
1344 switch (g_fSupHardenedMain & SUPSECMAIN_FLAGS_LOC_MASK)
1345 {
1346 case SUPSECMAIN_FLAGS_LOC_APP_BIN:
1347 break;
1348 case SUPSECMAIN_FLAGS_LOC_TESTCASE:
1349 suplibHardenedPathStripFilename(g_szSupLibHardenedAppBinPath);
1350 break;
1351 default:
1352 supR3HardenedFatal("supR3HardenedExecDir: Unknown program binary location: %#x\n", g_fSupHardenedMain);
1353 }
1354}
1355
1356
1357#ifdef RT_OS_LINUX
1358/**
1359 * Checks if we can read /proc/self/exe.
1360 *
1361 * This is used on linux to see if we have to call init
1362 * with program path or not.
1363 *
1364 * @returns true / false.
1365 */
1366static bool supR3HardenedMainIsProcSelfExeAccssible(void)
1367{
1368 char szPath[RTPATH_MAX];
1369 int cchLink = readlink("/proc/self/exe", szPath, sizeof(szPath));
1370 return cchLink != -1;
1371}
1372#endif /* RT_OS_LINUX */
1373
1374
1375
1376/**
1377 * @copydoc RTPathExecDir
1378 * @remarks not quite like RTPathExecDir actually...
1379 */
1380DECLHIDDEN(int) supR3HardenedPathAppBin(char *pszPath, size_t cchPath)
1381{
1382 /*
1383 * Lazy init (probably not required).
1384 */
1385 if (!g_szSupLibHardenedAppBinPath[0])
1386 supR3HardenedGetFullExePath();
1387
1388 /*
1389 * Calc the length and check if there is space before copying.
1390 */
1391 size_t cch = suplibHardenedStrLen(g_szSupLibHardenedAppBinPath) + 1;
1392 if (cch <= cchPath)
1393 {
1394 suplibHardenedMemCopy(pszPath, g_szSupLibHardenedAppBinPath, cch + 1);
1395 return VINF_SUCCESS;
1396 }
1397
1398 supR3HardenedFatal("supR3HardenedPathAppBin: Buffer too small (%u < %u)\n", cchPath, cch);
1399 /* not reached */
1400}
1401
1402
1403#ifdef RT_OS_WINDOWS
1404extern "C" uint32_t g_uNtVerCombined;
1405#endif
1406
1407DECLHIDDEN(void) supR3HardenedOpenLog(int *pcArgs, char **papszArgs)
1408{
1409 static const char s_szLogOption[] = "--sup-hardening-log=";
1410
1411 /*
1412 * Scan the argument vector.
1413 */
1414 int cArgs = *pcArgs;
1415 for (int iArg = 1; iArg < cArgs; iArg++)
1416 if (strncmp(papszArgs[iArg], s_szLogOption, sizeof(s_szLogOption) - 1) == 0)
1417 {
1418#ifdef RT_OS_WINDOWS
1419 const char *pszLogFile = &papszArgs[iArg][sizeof(s_szLogOption) - 1];
1420#endif
1421
1422 /*
1423 * Drop the argument from the vector (has trailing NULL entry).
1424 */
1425 memmove(&papszArgs[iArg], &papszArgs[iArg + 1], (cArgs - iArg) * sizeof(papszArgs[0]));
1426 *pcArgs -= 1;
1427 cArgs -= 1;
1428
1429 /*
1430 * Open the log file, unless we've already opened one.
1431 * First argument takes precedence
1432 */
1433#ifdef RT_OS_WINDOWS
1434 if (g_hStartupLog == NULL)
1435 {
1436 int rc = RTNtPathOpen(pszLogFile,
1437 GENERIC_WRITE | SYNCHRONIZE,
1438 FILE_ATTRIBUTE_NORMAL,
1439 FILE_SHARE_READ | FILE_SHARE_WRITE,
1440 FILE_OPEN_IF,
1441 FILE_NON_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT,
1442 OBJ_CASE_INSENSITIVE,
1443 &g_hStartupLog,
1444 NULL);
1445 if (RT_SUCCESS(rc))
1446 {
1447 SUP_DPRINTF(("Log file opened: " VBOX_VERSION_STRING "r%u g_hStartupLog=%p g_uNtVerCombined=%#x\n",
1448 VBOX_SVN_REV, g_hStartupLog, g_uNtVerCombined));
1449
1450 /*
1451 * If the path contains a drive volume, save it so we can
1452 * use it to flush the volume containing the log file.
1453 */
1454 if (RT_C_IS_ALPHA(pszLogFile[0]) && pszLogFile[1] == ':')
1455 {
1456 RTUtf16CopyAscii(g_wszStartupLogVol, RT_ELEMENTS(g_wszStartupLogVol), "\\??\\");
1457 g_wszStartupLogVol[sizeof("\\??\\") - 1] = RT_C_TO_UPPER(pszLogFile[0]);
1458 g_wszStartupLogVol[sizeof("\\??\\") + 0] = ':';
1459 g_wszStartupLogVol[sizeof("\\??\\") + 1] = '\0';
1460 }
1461 }
1462 else
1463 g_hStartupLog = NULL;
1464 }
1465#else
1466 /* Just some mumbo jumbo to shut up the compiler. */
1467 g_hStartupLog -= 1;
1468 g_cbStartupLog += 1;
1469 //g_hStartupLog = open()
1470#endif
1471 }
1472}
1473
1474
1475DECLHIDDEN(void) supR3HardenedLogV(const char *pszFormat, va_list va)
1476{
1477#ifdef RT_OS_WINDOWS
1478 if ( g_hStartupLog != NULL
1479 && g_cbStartupLog < 16*_1M)
1480 {
1481 char szBuf[5120];
1482 PCLIENT_ID pSelfId = &((PTEB)NtCurrentTeb())->ClientId;
1483 size_t cchPrefix = RTStrPrintf(szBuf, sizeof(szBuf), "%x.%x: ", pSelfId->UniqueProcess, pSelfId->UniqueThread);
1484 size_t cch = RTStrPrintfV(&szBuf[cchPrefix], sizeof(szBuf) - cchPrefix, pszFormat, va) + cchPrefix;
1485
1486 if ((size_t)cch >= sizeof(szBuf))
1487 cch = sizeof(szBuf) - 1;
1488
1489 if (!cch || szBuf[cch - 1] != '\n')
1490 szBuf[cch++] = '\n';
1491
1492 ASMAtomicAddU32(&g_cbStartupLog, (uint32_t)cch);
1493
1494 IO_STATUS_BLOCK Ios = RTNT_IO_STATUS_BLOCK_INITIALIZER;
1495 LARGE_INTEGER Offset;
1496 Offset.QuadPart = -1; /* Write to end of file. */
1497 NtWriteFile(g_hStartupLog, NULL /*Event*/, NULL /*ApcRoutine*/, NULL /*ApcContext*/,
1498 &Ios, szBuf, (ULONG)cch, &Offset, NULL /*Key*/);
1499 }
1500#else
1501 RT_NOREF(pszFormat, va);
1502 /* later */
1503#endif
1504}
1505
1506
1507DECLHIDDEN(void) supR3HardenedLog(const char *pszFormat, ...)
1508{
1509 va_list va;
1510 va_start(va, pszFormat);
1511 supR3HardenedLogV(pszFormat, va);
1512 va_end(va);
1513}
1514
1515
1516DECLHIDDEN(void) supR3HardenedLogFlush(void)
1517{
1518#ifdef RT_OS_WINDOWS
1519 if ( g_hStartupLog != NULL
1520 && g_cbStartupLog < 16*_1M)
1521 {
1522 IO_STATUS_BLOCK Ios = RTNT_IO_STATUS_BLOCK_INITIALIZER;
1523 NTSTATUS rcNt = NtFlushBuffersFile(g_hStartupLog, &Ios);
1524
1525 /*
1526 * Try flush the volume containing the log file too.
1527 */
1528 if (g_wszStartupLogVol[0])
1529 {
1530 HANDLE hLogVol = RTNT_INVALID_HANDLE_VALUE;
1531 UNICODE_STRING NtName;
1532 NtName.Buffer = g_wszStartupLogVol;
1533 NtName.Length = (USHORT)(RTUtf16Len(g_wszStartupLogVol) * sizeof(RTUTF16));
1534 NtName.MaximumLength = NtName.Length + 1;
1535 OBJECT_ATTRIBUTES ObjAttr;
1536 InitializeObjectAttributes(&ObjAttr, &NtName, OBJ_CASE_INSENSITIVE, NULL /*hRootDir*/, NULL /*pSecDesc*/);
1537 RTNT_IO_STATUS_BLOCK_REINIT(&Ios);
1538 rcNt = NtCreateFile(&hLogVol,
1539 GENERIC_WRITE | GENERIC_READ | SYNCHRONIZE | FILE_READ_ATTRIBUTES,
1540 &ObjAttr,
1541 &Ios,
1542 NULL /* Allocation Size*/,
1543 0 /*FileAttributes*/,
1544 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
1545 FILE_OPEN,
1546 FILE_NON_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT,
1547 NULL /*EaBuffer*/,
1548 0 /*EaLength*/);
1549 if (NT_SUCCESS(rcNt))
1550 rcNt = Ios.Status;
1551 if (NT_SUCCESS(rcNt))
1552 {
1553 RTNT_IO_STATUS_BLOCK_REINIT(&Ios);
1554 rcNt = NtFlushBuffersFile(hLogVol, &Ios);
1555 NtClose(hLogVol);
1556 }
1557 else
1558 {
1559 /* This may have sideeffects similar to what we want... */
1560 hLogVol = RTNT_INVALID_HANDLE_VALUE;
1561 RTNT_IO_STATUS_BLOCK_REINIT(&Ios);
1562 rcNt = NtCreateFile(&hLogVol,
1563 GENERIC_READ | SYNCHRONIZE | FILE_READ_ATTRIBUTES,
1564 &ObjAttr,
1565 &Ios,
1566 NULL /* Allocation Size*/,
1567 0 /*FileAttributes*/,
1568 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
1569 FILE_OPEN,
1570 FILE_NON_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT,
1571 NULL /*EaBuffer*/,
1572 0 /*EaLength*/);
1573 if (NT_SUCCESS(rcNt) && NT_SUCCESS(Ios.Status))
1574 NtClose(hLogVol);
1575 }
1576 }
1577 }
1578#else
1579 /* later */
1580#endif
1581}
1582
1583
1584/**
1585 * Prints the message prefix.
1586 */
1587static void suplibHardenedPrintPrefix(void)
1588{
1589 if (g_pszSupLibHardenedProgName)
1590 suplibHardenedPrintStr(g_pszSupLibHardenedProgName);
1591 suplibHardenedPrintStr(": ");
1592}
1593
1594
1595DECL_NO_RETURN(DECLHIDDEN(void)) supR3HardenedFatalMsgV(const char *pszWhere, SUPINITOP enmWhat, int rc,
1596 const char *pszMsgFmt, va_list va)
1597{
1598 /*
1599 * First to the log.
1600 */
1601 supR3HardenedLog("Error %d in %s! (enmWhat=%d)\n", rc, pszWhere, enmWhat);
1602 va_list vaCopy;
1603 va_copy(vaCopy, va);
1604 supR3HardenedLogV(pszMsgFmt, vaCopy);
1605 va_end(vaCopy);
1606
1607#ifdef RT_OS_WINDOWS
1608 /*
1609 * The release log.
1610 */
1611 if (g_pfnRTLogRelPrintf)
1612 {
1613 va_copy(vaCopy, va);
1614 g_pfnRTLogRelPrintf("supR3HardenedFatalMsgV: %s enmWhat=%d rc=%Rrc (%#x)\n", pszWhere, enmWhat, rc);
1615 g_pfnRTLogRelPrintf("supR3HardenedFatalMsgV: %N\n", pszMsgFmt, &vaCopy);
1616 va_end(vaCopy);
1617 }
1618#endif
1619
1620 /*
1621 * Then to the console.
1622 */
1623 suplibHardenedPrintPrefix();
1624 suplibHardenedPrintF("Error %d in %s!\n", rc, pszWhere);
1625
1626 suplibHardenedPrintPrefix();
1627 va_copy(vaCopy, va);
1628 suplibHardenedPrintFV(pszMsgFmt, vaCopy);
1629 va_end(vaCopy);
1630 suplibHardenedPrintChr('\n');
1631
1632 switch (enmWhat)
1633 {
1634 case kSupInitOp_Driver:
1635 suplibHardenedPrintChr('\n');
1636 suplibHardenedPrintPrefix();
1637 suplibHardenedPrintStr("Tip! Make sure the kernel module is loaded. It may also help to reinstall VirtualBox.\n");
1638 break;
1639
1640 case kSupInitOp_Misc:
1641 case kSupInitOp_IPRT:
1642 case kSupInitOp_Integrity:
1643 case kSupInitOp_RootCheck:
1644 suplibHardenedPrintChr('\n');
1645 suplibHardenedPrintPrefix();
1646 suplibHardenedPrintStr("Tip! It may help to reinstall VirtualBox.\n");
1647 break;
1648
1649 default:
1650 /* no hints here */
1651 break;
1652 }
1653
1654 /*
1655 * Finally, TrustedError if appropriate.
1656 */
1657 if (g_enmSupR3HardenedMainState >= SUPR3HARDENEDMAINSTATE_WIN_IMPORTS_RESOLVED)
1658 {
1659#ifdef SUP_HARDENED_SUID
1660 /*
1661 * Drop any root privileges we might be holding, this won't return
1662 * if it fails but end up calling supR3HardenedFatal[V].
1663 */
1664 supR3HardenedMainDropPrivileges();
1665#endif
1666
1667 suplibOsTerm(&g_SupPreInitData.Data);
1668
1669 /*
1670 * Now try resolve and call the TrustedError entry point if we can
1671 * find it. We'll fork before we attempt this because that way the
1672 * session management in main will see us exiting immediately (if
1673 * it's involved with us).
1674 */
1675#if !defined(RT_OS_WINDOWS) && !defined(RT_OS_OS2)
1676 int pid = fork();
1677 if (pid <= 0)
1678#endif
1679 {
1680 static volatile bool s_fRecursive = false; /* Loader hooks may cause recursion. */
1681 if (!s_fRecursive)
1682 {
1683 s_fRecursive = true;
1684
1685 PFNSUPTRUSTEDERROR pfnTrustedError = supR3HardenedMainGetTrustedError(g_pszSupLibHardenedProgName);
1686 if (pfnTrustedError)
1687 pfnTrustedError(pszWhere, enmWhat, rc, pszMsgFmt, va);
1688
1689 s_fRecursive = false;
1690 }
1691 }
1692 }
1693#if defined(RT_OS_WINDOWS)
1694 /*
1695 * Report the error to the parent if this happens during early VM init.
1696 */
1697 else if ( g_enmSupR3HardenedMainState < SUPR3HARDENEDMAINSTATE_WIN_IMPORTS_RESOLVED
1698 && g_enmSupR3HardenedMainState != SUPR3HARDENEDMAINSTATE_NOT_YET_CALLED)
1699 supR3HardenedWinReportErrorToParent(pszWhere, enmWhat, rc, pszMsgFmt, va);
1700#endif
1701
1702 /*
1703 * Quit
1704 */
1705 suplibHardenedExit(RTEXITCODE_FAILURE);
1706}
1707
1708
1709DECL_NO_RETURN(DECLHIDDEN(void)) supR3HardenedFatalMsg(const char *pszWhere, SUPINITOP enmWhat, int rc,
1710 const char *pszMsgFmt, ...)
1711{
1712 va_list va;
1713 va_start(va, pszMsgFmt);
1714 supR3HardenedFatalMsgV(pszWhere, enmWhat, rc, pszMsgFmt, va);
1715 /* not reached */
1716}
1717
1718
1719DECL_NO_RETURN(DECLHIDDEN(void)) supR3HardenedFatalV(const char *pszFormat, va_list va)
1720{
1721 supR3HardenedLog("Fatal error:\n");
1722 va_list vaCopy;
1723 va_copy(vaCopy, va);
1724 supR3HardenedLogV(pszFormat, vaCopy);
1725 va_end(vaCopy);
1726
1727#if defined(RT_OS_WINDOWS)
1728 /*
1729 * Report the error to the parent if this happens during early VM init.
1730 */
1731 if ( g_enmSupR3HardenedMainState < SUPR3HARDENEDMAINSTATE_WIN_IMPORTS_RESOLVED
1732 && g_enmSupR3HardenedMainState != SUPR3HARDENEDMAINSTATE_NOT_YET_CALLED)
1733 supR3HardenedWinReportErrorToParent(NULL, kSupInitOp_Invalid, VERR_INTERNAL_ERROR, pszFormat, va);
1734 else
1735#endif
1736 {
1737#ifdef RT_OS_WINDOWS
1738 if (g_pfnRTLogRelPrintf)
1739 {
1740 va_copy(vaCopy, va);
1741 g_pfnRTLogRelPrintf("supR3HardenedFatalV: %N", pszFormat, &vaCopy);
1742 va_end(vaCopy);
1743 }
1744#endif
1745
1746 suplibHardenedPrintPrefix();
1747 suplibHardenedPrintFV(pszFormat, va);
1748 }
1749
1750 suplibHardenedExit(RTEXITCODE_FAILURE);
1751}
1752
1753
1754DECL_NO_RETURN(DECLHIDDEN(void)) supR3HardenedFatal(const char *pszFormat, ...)
1755{
1756 va_list va;
1757 va_start(va, pszFormat);
1758 supR3HardenedFatalV(pszFormat, va);
1759 /* not reached */
1760}
1761
1762
1763DECLHIDDEN(int) supR3HardenedErrorV(int rc, bool fFatal, const char *pszFormat, va_list va)
1764{
1765 if (fFatal)
1766 supR3HardenedFatalV(pszFormat, va);
1767
1768 supR3HardenedLog("Error (rc=%d):\n", rc);
1769 va_list vaCopy;
1770 va_copy(vaCopy, va);
1771 supR3HardenedLogV(pszFormat, vaCopy);
1772 va_end(vaCopy);
1773
1774#ifdef RT_OS_WINDOWS
1775 if (g_pfnRTLogRelPrintf)
1776 {
1777 va_copy(vaCopy, va);
1778 g_pfnRTLogRelPrintf("supR3HardenedErrorV: %N", pszFormat, &vaCopy);
1779 va_end(vaCopy);
1780 }
1781#endif
1782
1783 suplibHardenedPrintPrefix();
1784 suplibHardenedPrintFV(pszFormat, va);
1785
1786 return rc;
1787}
1788
1789
1790DECLHIDDEN(int) supR3HardenedError(int rc, bool fFatal, const char *pszFormat, ...)
1791{
1792 va_list va;
1793 va_start(va, pszFormat);
1794 supR3HardenedErrorV(rc, fFatal, pszFormat, va);
1795 va_end(va);
1796 return rc;
1797}
1798
1799
1800
1801/**
1802 * Attempts to open /dev/vboxdrv (or equvivalent).
1803 *
1804 * @remarks This function will not return on failure.
1805 */
1806DECLHIDDEN(void) supR3HardenedMainOpenDevice(void)
1807{
1808 RTERRINFOSTATIC ErrInfo;
1809 SUPINITOP enmWhat = kSupInitOp_Driver;
1810 int rc = suplibOsInit(&g_SupPreInitData.Data, false /*fPreInit*/, true /*fUnrestricted*/,
1811 &enmWhat, RTErrInfoInitStatic(&ErrInfo));
1812 if (RT_SUCCESS(rc))
1813 return;
1814
1815 if (RTErrInfoIsSet(&ErrInfo.Core))
1816 supR3HardenedFatalMsg("suplibOsInit", enmWhat, rc, "%s", ErrInfo.szMsg);
1817
1818 switch (rc)
1819 {
1820 /** @todo better messages! */
1821 case VERR_VM_DRIVER_NOT_INSTALLED:
1822 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "Kernel driver not installed");
1823 case VERR_VM_DRIVER_NOT_ACCESSIBLE:
1824 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "Kernel driver not accessible");
1825 case VERR_VM_DRIVER_LOAD_ERROR:
1826 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "VERR_VM_DRIVER_LOAD_ERROR");
1827 case VERR_VM_DRIVER_OPEN_ERROR:
1828 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "VERR_VM_DRIVER_OPEN_ERROR");
1829 case VERR_VM_DRIVER_VERSION_MISMATCH:
1830 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "Kernel driver version mismatch");
1831 case VERR_ACCESS_DENIED:
1832 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "VERR_ACCESS_DENIED");
1833 case VERR_NO_MEMORY:
1834 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "Kernel memory allocation/mapping failed");
1835 case VERR_SUPDRV_HARDENING_EVIL_HANDLE:
1836 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Integrity, rc, "VERR_SUPDRV_HARDENING_EVIL_HANDLE");
1837 case VERR_SUPLIB_NT_PROCESS_UNTRUSTED_0:
1838 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Integrity, rc, "VERR_SUPLIB_NT_PROCESS_UNTRUSTED_0");
1839 case VERR_SUPLIB_NT_PROCESS_UNTRUSTED_1:
1840 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Integrity, rc, "VERR_SUPLIB_NT_PROCESS_UNTRUSTED_1");
1841 case VERR_SUPLIB_NT_PROCESS_UNTRUSTED_2:
1842 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Integrity, rc, "VERR_SUPLIB_NT_PROCESS_UNTRUSTED_2");
1843 default:
1844 supR3HardenedFatalMsg("suplibOsInit", kSupInitOp_Driver, rc, "Unknown rc=%d (%Rrc)", rc, rc);
1845 }
1846}
1847
1848
1849#ifdef SUP_HARDENED_SUID
1850
1851/**
1852 * Grabs extra non-root capabilities / privileges that we might require.
1853 *
1854 * This is currently only used for being able to do ICMP from the NAT engine.
1855 *
1856 * @note We still have root privileges at the time of this call.
1857 */
1858static void supR3HardenedMainGrabCapabilites(void)
1859{
1860# if defined(RT_OS_LINUX)
1861 /*
1862 * We are about to drop all our privileges. Remove all capabilities but
1863 * keep the cap_net_raw capability for ICMP sockets for the NAT stack.
1864 */
1865 if (g_uCaps != 0)
1866 {
1867# ifdef USE_LIB_PCAP
1868 /* XXX cap_net_bind_service */
1869 if (!cap_set_proc(cap_from_text("all-eip cap_net_raw+ep")))
1870 prctl(PR_SET_KEEPCAPS, 1 /*keep=*/, 0, 0, 0);
1871 prctl(PR_SET_DUMPABLE, 1 /*dump*/, 0, 0, 0);
1872# else
1873 cap_user_header_t hdr = (cap_user_header_t)alloca(sizeof(*hdr));
1874 cap_user_data_t cap = (cap_user_data_t)alloca(2 /*_LINUX_CAPABILITY_U32S_3*/ * sizeof(*cap));
1875 memset(hdr, 0, sizeof(*hdr));
1876 capget(hdr, NULL);
1877 if ( hdr->version != 0x19980330 /* _LINUX_CAPABILITY_VERSION_1, _LINUX_CAPABILITY_U32S_1 = 1 */
1878 && hdr->version != 0x20071026 /* _LINUX_CAPABILITY_VERSION_2, _LINUX_CAPABILITY_U32S_2 = 2 */
1879 && hdr->version != 0x20080522 /* _LINUX_CAPABILITY_VERSION_3, _LINUX_CAPABILITY_U32S_3 = 2 */)
1880 hdr->version = _LINUX_CAPABILITY_VERSION;
1881 g_uCapsVersion = hdr->version;
1882 memset(cap, 0, 2 /* _LINUX_CAPABILITY_U32S_3 */ * sizeof(*cap));
1883 cap->effective = g_uCaps;
1884 cap->permitted = g_uCaps;
1885 if (!capset(hdr, cap))
1886 prctl(PR_SET_KEEPCAPS, 1 /*keep*/, 0, 0, 0);
1887 prctl(PR_SET_DUMPABLE, 1 /*dump*/, 0, 0, 0);
1888# endif /* !USE_LIB_PCAP */
1889 }
1890
1891# elif defined(RT_OS_SOLARIS)
1892 /*
1893 * Add net_icmpaccess privilege to effective privileges and limit
1894 * permitted privileges before completely dropping root privileges.
1895 * This requires dropping root privileges temporarily to get the normal
1896 * user's privileges.
1897 */
1898 seteuid(g_uid);
1899 priv_set_t *pPrivEffective = priv_allocset();
1900 priv_set_t *pPrivNew = priv_allocset();
1901 if (pPrivEffective && pPrivNew)
1902 {
1903 int rc = getppriv(PRIV_EFFECTIVE, pPrivEffective);
1904 seteuid(0);
1905 if (!rc)
1906 {
1907 priv_copyset(pPrivEffective, pPrivNew);
1908 rc = priv_addset(pPrivNew, PRIV_NET_ICMPACCESS);
1909 if (!rc)
1910 {
1911 /* Order is important, as one can't set a privilege which is
1912 * not in the permitted privilege set. */
1913 rc = setppriv(PRIV_SET, PRIV_EFFECTIVE, pPrivNew);
1914 if (rc)
1915 supR3HardenedError(rc, false, "SUPR3HardenedMain: failed to set effective privilege set.\n");
1916 rc = setppriv(PRIV_SET, PRIV_PERMITTED, pPrivNew);
1917 if (rc)
1918 supR3HardenedError(rc, false, "SUPR3HardenedMain: failed to set permitted privilege set.\n");
1919 }
1920 else
1921 supR3HardenedError(rc, false, "SUPR3HardenedMain: failed to add NET_ICMPACCESS privilege.\n");
1922 }
1923 }
1924 else
1925 {
1926 /* for memory allocation failures just continue */
1927 seteuid(0);
1928 }
1929
1930 if (pPrivEffective)
1931 priv_freeset(pPrivEffective);
1932 if (pPrivNew)
1933 priv_freeset(pPrivNew);
1934# endif
1935}
1936
1937/*
1938 * Look at the environment for some special options.
1939 */
1940static void supR3GrabOptions(void)
1941{
1942# ifdef RT_OS_LINUX
1943 g_uCaps = 0;
1944
1945 /*
1946 * Do _not_ perform any capability-related system calls for root processes
1947 * (leaving g_uCaps at 0).
1948 * (Hint: getuid gets the real user id, not the effective.)
1949 */
1950 if (getuid() != 0)
1951 {
1952 /*
1953 * CAP_NET_RAW.
1954 * Default: enabled.
1955 * Can be disabled with 'export VBOX_HARD_CAP_NET_RAW=0'.
1956 */
1957 const char *pszOpt = getenv("VBOX_HARD_CAP_NET_RAW");
1958 if ( !pszOpt
1959 || memcmp(pszOpt, "0", sizeof("0")) != 0)
1960 g_uCaps = CAP_TO_MASK(CAP_NET_RAW);
1961
1962 /*
1963 * CAP_NET_BIND_SERVICE.
1964 * Default: disabled.
1965 * Can be enabled with 'export VBOX_HARD_CAP_NET_BIND_SERVICE=1'.
1966 */
1967 pszOpt = getenv("VBOX_HARD_CAP_NET_BIND_SERVICE");
1968 if ( pszOpt
1969 && memcmp(pszOpt, "0", sizeof("0")) != 0)
1970 g_uCaps |= CAP_TO_MASK(CAP_NET_BIND_SERVICE);
1971 }
1972# endif
1973}
1974
1975/**
1976 * Drop any root privileges we might be holding.
1977 */
1978static void supR3HardenedMainDropPrivileges(void)
1979{
1980 /*
1981 * Try use setre[ug]id since this will clear the save uid/gid and thus
1982 * leave fewer traces behind that libs like GTK+ may pick up.
1983 */
1984 uid_t euid, ruid, suid;
1985 gid_t egid, rgid, sgid;
1986# if defined(RT_OS_DARWIN)
1987 /* The really great thing here is that setreuid isn't available on
1988 OS X 10.4, libc emulates it. While 10.4 have a slightly different and
1989 non-standard setuid implementation compared to 10.5, the following
1990 works the same way with both version since we're super user (10.5 req).
1991 The following will set all three variants of the group and user IDs. */
1992 setgid(g_gid);
1993 setuid(g_uid);
1994 euid = geteuid();
1995 ruid = suid = getuid();
1996 egid = getegid();
1997 rgid = sgid = getgid();
1998
1999# elif defined(RT_OS_SOLARIS)
2000 /* Solaris doesn't have setresuid, but the setreuid interface is BSD
2001 compatible and will set the saved uid to euid when we pass it a ruid
2002 that isn't -1 (which we do). */
2003 setregid(g_gid, g_gid);
2004 setreuid(g_uid, g_uid);
2005 euid = geteuid();
2006 ruid = suid = getuid();
2007 egid = getegid();
2008 rgid = sgid = getgid();
2009
2010# else
2011 /* This is the preferred one, full control no questions about semantics.
2012 PORTME: If this isn't work, try join one of two other gangs above. */
2013 int res = setresgid(g_gid, g_gid, g_gid);
2014 NOREF(res);
2015 res = setresuid(g_uid, g_uid, g_uid);
2016 NOREF(res);
2017 if (getresuid(&ruid, &euid, &suid) != 0)
2018 {
2019 euid = geteuid();
2020 ruid = suid = getuid();
2021 }
2022 if (getresgid(&rgid, &egid, &sgid) != 0)
2023 {
2024 egid = getegid();
2025 rgid = sgid = getgid();
2026 }
2027# endif
2028
2029
2030 /* Check that it worked out all right. */
2031 if ( euid != g_uid
2032 || ruid != g_uid
2033 || suid != g_uid
2034 || egid != g_gid
2035 || rgid != g_gid
2036 || sgid != g_gid)
2037 supR3HardenedFatal("SUPR3HardenedMain: failed to drop root privileges!"
2038 " (euid=%d ruid=%d suid=%d egid=%d rgid=%d sgid=%d; wanted uid=%d and gid=%d)\n",
2039 euid, ruid, suid, egid, rgid, sgid, g_uid, g_gid);
2040
2041# if RT_OS_LINUX
2042 /*
2043 * Re-enable the cap_net_raw capability which was disabled during setresuid.
2044 */
2045 if (g_uCaps != 0)
2046 {
2047# ifdef USE_LIB_PCAP
2048 /** @todo Warn if that does not work? */
2049 /* XXX cap_net_bind_service */
2050 cap_set_proc(cap_from_text("cap_net_raw+ep"));
2051# else
2052 cap_user_header_t hdr = (cap_user_header_t)alloca(sizeof(*hdr));
2053 cap_user_data_t cap = (cap_user_data_t)alloca(2 /* _LINUX_CAPABILITY_U32S_3 */ * sizeof(*cap));
2054 memset(hdr, 0, sizeof(*hdr));
2055 hdr->version = g_uCapsVersion;
2056 memset(cap, 0, 2 /* _LINUX_CAPABILITY_U32S_3 */ * sizeof(*cap));
2057 cap->effective = g_uCaps;
2058 cap->permitted = g_uCaps;
2059 /** @todo Warn if that does not work? */
2060 capset(hdr, cap);
2061# endif /* !USE_LIB_PCAP */
2062 }
2063# endif
2064}
2065
2066#endif /* SUP_HARDENED_SUID */
2067
2068/**
2069 * Purge the process environment from any environment vairable which can lead
2070 * to loading untrusted binaries compromising the process address space.
2071 *
2072 * @param envp The initial environment vector. (Can be NULL.)
2073 */
2074static void supR3HardenedMainPurgeEnvironment(char **envp)
2075{
2076 for (unsigned i = 0; i < RT_ELEMENTS(g_aSupEnvPurgeDescs); i++)
2077 {
2078 /*
2079 * Update the initial environment vector, just in case someone actually cares about it.
2080 */
2081 if (envp)
2082 {
2083 const char * const pszEnv = g_aSupEnvPurgeDescs[i].pszEnv;
2084 size_t const cchEnv = g_aSupEnvPurgeDescs[i].cchEnv;
2085 unsigned iSrc = 0;
2086 unsigned iDst = 0;
2087 char *pszTmp;
2088
2089 while ((pszTmp = envp[iSrc]) != NULL)
2090 {
2091 if ( memcmp(pszTmp, pszEnv, cchEnv) != 0
2092 || (pszTmp[cchEnv] != '=' && pszTmp[cchEnv] != '\0'))
2093 {
2094 if (iDst != iSrc)
2095 envp[iDst] = pszTmp;
2096 iDst++;
2097 }
2098 else
2099 SUP_DPRINTF(("supR3HardenedMainPurgeEnvironment: dropping envp[%d]=%s\n", iSrc, pszTmp));
2100 iSrc++;
2101 }
2102
2103 if (iDst != iSrc)
2104 while (iDst <= iSrc)
2105 envp[iDst++] = NULL;
2106 }
2107
2108 /*
2109 * Remove from the process environment if present.
2110 */
2111#ifndef RT_OS_WINDOWS
2112 const char *pszTmp = getenv(g_aSupEnvPurgeDescs[i].pszEnv);
2113 if (pszTmp != NULL)
2114 {
2115 if (unsetenv((char *)g_aSupEnvPurgeDescs[i].pszEnv) == 0)
2116 SUP_DPRINTF(("supR3HardenedMainPurgeEnvironment: dropped %s\n", pszTmp));
2117 else
2118 if (g_aSupEnvPurgeDescs[i].fPurgeErrFatal)
2119 supR3HardenedFatal("SUPR3HardenedMain: failed to purge %s environment variable! (errno=%d %s)\n",
2120 g_aSupEnvPurgeDescs[i].pszEnv, errno, strerror(errno));
2121 else
2122 SUP_DPRINTF(("supR3HardenedMainPurgeEnvironment: dropping %s failed! errno=%d\n", pszTmp, errno));
2123 }
2124#else
2125 /** @todo Call NT API to do the same. */
2126#endif
2127 }
2128}
2129
2130
2131/**
2132 * Returns the argument purge descriptor of the given argument if available.
2133 *
2134 * @retval 0 if it should not be purged.
2135 * @retval 1 if it only the current argument should be purged.
2136 * @retval 2 if the argument and the following (if present) should be purged.
2137 * @param pszArg The argument to look for.
2138 */
2139static unsigned supR3HardenedMainShouldPurgeArg(const char *pszArg)
2140{
2141 for (unsigned i = 0; i < RT_ELEMENTS(g_aSupArgPurgeDescs); i++)
2142 {
2143 size_t const cchPurge = g_aSupArgPurgeDescs[i].cchArg;
2144 if (!memcmp(pszArg, g_aSupArgPurgeDescs[i].pszArg, cchPurge))
2145 {
2146 if (pszArg[cchPurge] == '\0')
2147 return 1 + g_aSupArgPurgeDescs[i].fTakesValue;
2148 if ( g_aSupArgPurgeDescs[i].fTakesValue
2149 && (pszArg[cchPurge] == ':' || pszArg[cchPurge] == '='))
2150 return 1;
2151 }
2152 }
2153
2154 return 0;
2155}
2156
2157
2158/**
2159 * Purges any command line arguments considered harmful.
2160 *
2161 * @returns nothing.
2162 * @param cArgsOrig The original number of arguments.
2163 * @param papszArgsOrig The original argument vector.
2164 * @param pcArgsNew Where to store the new number of arguments on success.
2165 * @param ppapszArgsNew Where to store the pointer to the purged argument vector.
2166 */
2167static void supR3HardenedMainPurgeArgs(int cArgsOrig, char **papszArgsOrig, int *pcArgsNew, char ***ppapszArgsNew)
2168{
2169 int iDst = 0;
2170#ifdef RT_OS_WINDOWS
2171 char **papszArgsNew = papszArgsOrig; /* We allocated this, no need to allocate again. */
2172#else
2173 char **papszArgsNew = (char **)malloc((cArgsOrig + 1) * sizeof(char *));
2174#endif
2175 if (papszArgsNew)
2176 {
2177 for (int iSrc = 0; iSrc < cArgsOrig; iSrc++)
2178 {
2179 unsigned cPurgedArgs = supR3HardenedMainShouldPurgeArg(papszArgsOrig[iSrc]);
2180 if (!cPurgedArgs)
2181 papszArgsNew[iDst++] = papszArgsOrig[iSrc];
2182 else
2183 iSrc += cPurgedArgs - 1;
2184 }
2185
2186 papszArgsNew[iDst] = NULL; /* The array is NULL terminated, just like envp. */
2187 }
2188 else
2189 supR3HardenedFatal("SUPR3HardenedMain: failed to allocate memory for purged command line!\n");
2190 *pcArgsNew = iDst;
2191 *ppapszArgsNew = papszArgsNew;
2192
2193#ifdef RT_OS_WINDOWS
2194 /** @todo Update command line pointers in PEB, wont really work without it. */
2195#endif
2196}
2197
2198
2199/**
2200 * Loads the VBoxRT DLL/SO/DYLIB, hands it the open driver,
2201 * and calls RTR3InitEx.
2202 *
2203 * @param fFlags The SUPR3HardenedMain fFlags argument, passed to supR3PreInit.
2204 *
2205 * @remarks VBoxRT contains both IPRT and SUPR3.
2206 * @remarks This function will not return on failure.
2207 */
2208static void supR3HardenedMainInitRuntime(uint32_t fFlags)
2209{
2210 /*
2211 * Construct the name.
2212 */
2213 char szPath[RTPATH_MAX];
2214 supR3HardenedPathAppSharedLibs(szPath, sizeof(szPath) - sizeof("/VBoxRT" SUPLIB_DLL_SUFF));
2215 suplibHardenedStrCat(szPath, "/VBoxRT" SUPLIB_DLL_SUFF);
2216
2217 /*
2218 * Open it and resolve the symbols.
2219 */
2220#if defined(RT_OS_WINDOWS)
2221 HMODULE hMod = (HMODULE)supR3HardenedWinLoadLibrary(szPath, false /*fSystem32Only*/, g_fSupHardenedMain);
2222 if (!hMod)
2223 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, VERR_MODULE_NOT_FOUND,
2224 "LoadLibrary \"%s\" failed (rc=%d)",
2225 szPath, RtlGetLastWin32Error());
2226 PFNRTR3INITEX pfnRTInitEx = (PFNRTR3INITEX)GetProcAddress(hMod, SUP_HARDENED_SYM("RTR3InitEx"));
2227 if (!pfnRTInitEx)
2228 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, VERR_SYMBOL_NOT_FOUND,
2229 "Entrypoint \"RTR3InitEx\" not found in \"%s\" (rc=%d)",
2230 szPath, RtlGetLastWin32Error());
2231
2232 PFNSUPR3PREINIT pfnSUPPreInit = (PFNSUPR3PREINIT)GetProcAddress(hMod, SUP_HARDENED_SYM("supR3PreInit"));
2233 if (!pfnSUPPreInit)
2234 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, VERR_SYMBOL_NOT_FOUND,
2235 "Entrypoint \"supR3PreInit\" not found in \"%s\" (rc=%d)",
2236 szPath, RtlGetLastWin32Error());
2237
2238 g_pfnRTLogRelPrintf = (PFNRTLOGRELPRINTF)GetProcAddress(hMod, SUP_HARDENED_SYM("RTLogRelPrintf"));
2239 Assert(g_pfnRTLogRelPrintf); /* Not fatal in non-strict builds. */
2240
2241#else
2242 /* the dlopen crowd */
2243 void *pvMod = dlopen(szPath, RTLD_NOW | RTLD_GLOBAL);
2244 if (!pvMod)
2245 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, VERR_MODULE_NOT_FOUND,
2246 "dlopen(\"%s\",) failed: %s",
2247 szPath, dlerror());
2248 PFNRTR3INITEX pfnRTInitEx = (PFNRTR3INITEX)(uintptr_t)dlsym(pvMod, SUP_HARDENED_SYM("RTR3InitEx"));
2249 if (!pfnRTInitEx)
2250 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, VERR_SYMBOL_NOT_FOUND,
2251 "Entrypoint \"RTR3InitEx\" not found in \"%s\"!\ndlerror: %s",
2252 szPath, dlerror());
2253 PFNSUPR3PREINIT pfnSUPPreInit = (PFNSUPR3PREINIT)(uintptr_t)dlsym(pvMod, SUP_HARDENED_SYM("supR3PreInit"));
2254 if (!pfnSUPPreInit)
2255 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, VERR_SYMBOL_NOT_FOUND,
2256 "Entrypoint \"supR3PreInit\" not found in \"%s\"!\ndlerror: %s",
2257 szPath, dlerror());
2258#endif
2259
2260 /*
2261 * Make the calls.
2262 */
2263 supR3HardenedGetPreInitData(&g_SupPreInitData);
2264 int rc = pfnSUPPreInit(&g_SupPreInitData, fFlags);
2265 if (RT_FAILURE(rc))
2266 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, rc,
2267 "supR3PreInit failed with rc=%d", rc);
2268 const char *pszExePath = NULL;
2269#ifdef RT_OS_LINUX
2270 if (!supR3HardenedMainIsProcSelfExeAccssible())
2271 pszExePath = g_szSupLibHardenedExePath;
2272#endif
2273 rc = pfnRTInitEx(RTR3INIT_VER_1,
2274 fFlags & SUPSECMAIN_FLAGS_DONT_OPEN_DEV ? 0 : RTR3INIT_FLAGS_SUPLIB,
2275 0 /*cArgs*/, NULL /*papszArgs*/, pszExePath);
2276 if (RT_FAILURE(rc))
2277 supR3HardenedFatalMsg("supR3HardenedMainInitRuntime", kSupInitOp_IPRT, rc,
2278 "RTR3InitEx failed with rc=%d", rc);
2279
2280#if defined(RT_OS_WINDOWS)
2281 /*
2282 * Windows: Create thread that terminates the process when the parent stub
2283 * process terminates (VBoxNetDHCP, Ctrl-C, etc).
2284 */
2285 if (!(fFlags & SUPSECMAIN_FLAGS_DONT_OPEN_DEV))
2286 supR3HardenedWinCreateParentWatcherThread(hMod);
2287#endif
2288}
2289
2290
2291/**
2292 * Construct the path to the DLL/SO/DYLIB containing the actual program.
2293 *
2294 * @returns VBox status code.
2295 * @param pszProgName The program name.
2296 * @param fMainFlags The flags passed to SUPR3HardenedMain.
2297 * @param pszPath The output buffer.
2298 * @param cbPath The size of the output buffer, in bytes. Must be at
2299 * least 128 bytes!
2300 */
2301static int supR3HardenedMainGetTrustedLib(const char *pszProgName, uint32_t fMainFlags, char *pszPath, size_t cbPath)
2302{
2303 supR3HardenedPathAppPrivateArch(pszPath, sizeof(cbPath) - 10);
2304 const char *pszSubDirSlash;
2305 switch (g_fSupHardenedMain & SUPSECMAIN_FLAGS_LOC_MASK)
2306 {
2307 case SUPSECMAIN_FLAGS_LOC_APP_BIN:
2308 pszSubDirSlash = "/";
2309 break;
2310 case SUPSECMAIN_FLAGS_LOC_TESTCASE:
2311 pszSubDirSlash = "/testcase/";
2312 break;
2313 default:
2314 pszSubDirSlash = "/";
2315 supR3HardenedFatal("supR3HardenedMainGetTrustedMain: Unknown program binary location: %#x\n", g_fSupHardenedMain);
2316 }
2317#ifdef RT_OS_DARWIN
2318 if (fMainFlags & SUPSECMAIN_FLAGS_OSX_VM_APP)
2319 pszProgName = "VirtualBox";
2320#else
2321 RT_NOREF1(fMainFlags);
2322#endif
2323 size_t cch = suplibHardenedStrLen(pszPath);
2324 return suplibHardenedStrCopyEx(&pszPath[cch], cbPath - cch, pszSubDirSlash, pszProgName, SUPLIB_DLL_SUFF, NULL);
2325}
2326
2327
2328/**
2329 * Loads the DLL/SO/DYLIB containing the actual program and
2330 * resolves the TrustedError symbol.
2331 *
2332 * This is very similar to supR3HardenedMainGetTrustedMain().
2333 *
2334 * @returns Pointer to the trusted error symbol if it is exported, NULL
2335 * and no error messages otherwise.
2336 * @param pszProgName The program name.
2337 */
2338static PFNSUPTRUSTEDERROR supR3HardenedMainGetTrustedError(const char *pszProgName)
2339{
2340 /*
2341 * Don't bother if the main() function didn't advertise any TrustedError
2342 * export. It's both a waste of time and may trigger additional problems,
2343 * confusing or obscuring the original issue.
2344 */
2345 if (!(g_fSupHardenedMain & SUPSECMAIN_FLAGS_TRUSTED_ERROR))
2346 return NULL;
2347
2348 /*
2349 * Construct the name.
2350 */
2351 char szPath[RTPATH_MAX];
2352 supR3HardenedMainGetTrustedLib(pszProgName, g_fSupHardenedMain, szPath, sizeof(szPath));
2353
2354 /*
2355 * Open it and resolve the symbol.
2356 */
2357#if defined(RT_OS_WINDOWS)
2358 supR3HardenedWinEnableThreadCreation();
2359 HMODULE hMod = (HMODULE)supR3HardenedWinLoadLibrary(szPath, false /*fSystem32Only*/, 0 /*fMainFlags*/);
2360 if (!hMod)
2361 return NULL;
2362 FARPROC pfn = GetProcAddress(hMod, SUP_HARDENED_SYM("TrustedError"));
2363 if (!pfn)
2364 return NULL;
2365 return (PFNSUPTRUSTEDERROR)pfn;
2366
2367#else
2368 /* the dlopen crowd */
2369 void *pvMod = dlopen(szPath, RTLD_NOW | RTLD_GLOBAL);
2370 if (!pvMod)
2371 return NULL;
2372 void *pvSym = dlsym(pvMod, SUP_HARDENED_SYM("TrustedError"));
2373 if (!pvSym)
2374 return NULL;
2375 return (PFNSUPTRUSTEDERROR)(uintptr_t)pvSym;
2376#endif
2377}
2378
2379
2380/**
2381 * Loads the DLL/SO/DYLIB containing the actual program and
2382 * resolves the TrustedMain symbol.
2383 *
2384 * @returns Pointer to the trusted main of the actual program.
2385 * @param pszProgName The program name.
2386 * @param fMainFlags The flags passed to SUPR3HardenedMain.
2387 * @remarks This function will not return on failure.
2388 */
2389static PFNSUPTRUSTEDMAIN supR3HardenedMainGetTrustedMain(const char *pszProgName, uint32_t fMainFlags)
2390{
2391 /*
2392 * Construct the name.
2393 */
2394 char szPath[RTPATH_MAX];
2395 supR3HardenedMainGetTrustedLib(pszProgName, fMainFlags, szPath, sizeof(szPath));
2396
2397 /*
2398 * Open it and resolve the symbol.
2399 */
2400#if defined(RT_OS_WINDOWS)
2401 HMODULE hMod = (HMODULE)supR3HardenedWinLoadLibrary(szPath, false /*fSystem32Only*/, 0 /*fMainFlags*/);
2402 if (!hMod)
2403 supR3HardenedFatal("supR3HardenedMainGetTrustedMain: LoadLibrary \"%s\" failed, rc=%d\n",
2404 szPath, RtlGetLastWin32Error());
2405 FARPROC pfn = GetProcAddress(hMod, SUP_HARDENED_SYM("TrustedMain"));
2406 if (!pfn)
2407 supR3HardenedFatal("supR3HardenedMainGetTrustedMain: Entrypoint \"TrustedMain\" not found in \"%s\" (rc=%d)\n",
2408 szPath, RtlGetLastWin32Error());
2409 return (PFNSUPTRUSTEDMAIN)pfn;
2410
2411#else
2412 /* the dlopen crowd */
2413 void *pvMod = dlopen(szPath, RTLD_NOW | RTLD_GLOBAL);
2414 if (!pvMod)
2415 supR3HardenedFatal("supR3HardenedMainGetTrustedMain: dlopen(\"%s\",) failed: %s\n",
2416 szPath, dlerror());
2417 void *pvSym = dlsym(pvMod, SUP_HARDENED_SYM("TrustedMain"));
2418 if (!pvSym)
2419 supR3HardenedFatal("supR3HardenedMainGetTrustedMain: Entrypoint \"TrustedMain\" not found in \"%s\"!\ndlerror: %s\n",
2420 szPath, dlerror());
2421 return (PFNSUPTRUSTEDMAIN)(uintptr_t)pvSym;
2422#endif
2423}
2424
2425
2426/**
2427 * Secure main.
2428 *
2429 * This is used for the set-user-ID-on-execute binaries on unixy systems
2430 * and when using the open-vboxdrv-via-root-service setup on Windows.
2431 *
2432 * This function will perform the integrity checks of the VirtualBox
2433 * installation, open the support driver, open the root service (later),
2434 * and load the DLL corresponding to \a pszProgName and execute its main
2435 * function.
2436 *
2437 * @returns Return code appropriate for main().
2438 *
2439 * @param pszProgName The program name. This will be used to figure out which
2440 * DLL/SO/DYLIB to load and execute.
2441 * @param fFlags Flags.
2442 * @param argc The argument count.
2443 * @param argv The argument vector.
2444 * @param envp The environment vector.
2445 */
2446DECLHIDDEN(int) SUPR3HardenedMain(const char *pszProgName, uint32_t fFlags, int argc, char **argv, char **envp)
2447{
2448 SUP_DPRINTF(("SUPR3HardenedMain: pszProgName=%s fFlags=%#x\n", pszProgName, fFlags));
2449 g_enmSupR3HardenedMainState = SUPR3HARDENEDMAINSTATE_HARDENED_MAIN_CALLED;
2450
2451 /*
2452 * Note! At this point there is no IPRT, so we will have to stick
2453 * to basic CRT functions that everyone agree upon.
2454 */
2455 g_pszSupLibHardenedProgName = pszProgName;
2456 g_fSupHardenedMain = fFlags;
2457 g_SupPreInitData.u32Magic = SUPPREINITDATA_MAGIC;
2458 g_SupPreInitData.u32EndMagic = SUPPREINITDATA_MAGIC;
2459#ifdef RT_OS_WINDOWS
2460 if (!g_fSupEarlyProcessInit)
2461#endif
2462 g_SupPreInitData.Data.hDevice = SUP_HDEVICE_NIL;
2463
2464 /*
2465 * Determine the full exe path as we'll be needing it for the verify all
2466 * call(s) below. (We have to do this early on Linux because we * *might*
2467 * not be able to access /proc/self/exe after the seteuid call.)
2468 */
2469 supR3HardenedGetFullExePath();
2470#ifdef RT_OS_WINDOWS
2471 supR3HardenedWinInitAppBin(fFlags);
2472#endif
2473
2474#ifdef SUP_HARDENED_SUID
2475 /*
2476 * Grab any options from the environment.
2477 */
2478 supR3GrabOptions();
2479
2480 /*
2481 * Check that we're root, if we aren't then the installation is butchered.
2482 */
2483 g_uid = getuid();
2484 g_gid = getgid();
2485 if (geteuid() != 0 /* root */)
2486 supR3HardenedFatalMsg("SUPR3HardenedMain", kSupInitOp_RootCheck, VERR_PERMISSION_DENIED,
2487 "Effective UID is not root (euid=%d egid=%d uid=%d gid=%d)",
2488 geteuid(), getegid(), g_uid, g_gid);
2489#endif /* SUP_HARDENED_SUID */
2490
2491#ifdef RT_OS_WINDOWS
2492 /*
2493 * Windows: First respawn. On Windows we will respawn the process twice to establish
2494 * something we can put some kind of reliable trust in. The first respawning aims
2495 * at dropping compatibility layers and process "security" solutions.
2496 */
2497 if ( !g_fSupEarlyProcessInit
2498 && !(fFlags & SUPSECMAIN_FLAGS_DONT_OPEN_DEV)
2499 && supR3HardenedWinIsReSpawnNeeded(1 /*iWhich*/, argc, argv))
2500 {
2501 SUP_DPRINTF(("SUPR3HardenedMain: Respawn #1\n"));
2502 supR3HardenedWinInit(SUPSECMAIN_FLAGS_DONT_OPEN_DEV, false /*fAvastKludge*/);
2503 supR3HardenedVerifyAll(true /* fFatal */, pszProgName, g_szSupLibHardenedExePath, fFlags);
2504 return supR3HardenedWinReSpawn(1 /*iWhich*/);
2505 }
2506
2507 /*
2508 * Windows: Initialize the image verification global data so we can verify the
2509 * signature of the process image and hook the core of the DLL loader API so we
2510 * can check the signature of all DLLs mapped into the process. (Already done
2511 * by early VM process init.)
2512 */
2513 if (!g_fSupEarlyProcessInit)
2514 supR3HardenedWinInit(fFlags, true /*fAvastKludge*/);
2515#endif /* RT_OS_WINDOWS */
2516
2517 /*
2518 * Validate the installation.
2519 */
2520 supR3HardenedVerifyAll(true /* fFatal */, pszProgName, g_szSupLibHardenedExePath, fFlags);
2521
2522 /*
2523 * The next steps are only taken if we actually need to access the support
2524 * driver. (Already done by early process init.)
2525 */
2526 if (!(fFlags & SUPSECMAIN_FLAGS_DONT_OPEN_DEV))
2527 {
2528#ifdef RT_OS_WINDOWS
2529 /*
2530 * Windows: Must have done early process init if we get here.
2531 */
2532 if (!g_fSupEarlyProcessInit)
2533 supR3HardenedFatalMsg("SUPR3HardenedMain", kSupInitOp_Integrity, VERR_WRONG_ORDER,
2534 "Early process init was somehow skipped.");
2535
2536 /*
2537 * Windows: The second respawn. This time we make a special arrangement
2538 * with vboxdrv to monitor access to the new process from its inception.
2539 */
2540 if (supR3HardenedWinIsReSpawnNeeded(2 /* iWhich*/, argc, argv))
2541 {
2542 SUP_DPRINTF(("SUPR3HardenedMain: Respawn #2\n"));
2543 return supR3HardenedWinReSpawn(2 /* iWhich*/);
2544 }
2545 SUP_DPRINTF(("SUPR3HardenedMain: Final process, opening VBoxDrv...\n"));
2546 supR3HardenedWinFlushLoaderCache();
2547
2548#else
2549 /*
2550 * Open the vboxdrv device.
2551 */
2552 supR3HardenedMainOpenDevice();
2553#endif /* !RT_OS_WINDOWS */
2554 }
2555
2556#ifdef RT_OS_WINDOWS
2557 /*
2558 * Windows: Enable the use of windows APIs to verify images at load time.
2559 */
2560 supR3HardenedWinEnableThreadCreation();
2561 supR3HardenedWinFlushLoaderCache();
2562 supR3HardenedWinResolveVerifyTrustApiAndHookThreadCreation(g_pszSupLibHardenedProgName);
2563 g_enmSupR3HardenedMainState = SUPR3HARDENEDMAINSTATE_WIN_VERIFY_TRUST_READY;
2564#else /* !RT_OS_WINDOWS */
2565# ifndef RT_OS_FREEBSD /** @todo portme */
2566 /*
2567 * Posix: Hook the load library interface interface.
2568 */
2569 supR3HardenedPosixInit();
2570# endif
2571#endif /* !RT_OS_WINDOWS */
2572
2573#ifdef SUP_HARDENED_SUID
2574 /*
2575 * Grab additional capabilities / privileges.
2576 */
2577 supR3HardenedMainGrabCapabilites();
2578
2579 /*
2580 * Drop any root privileges we might be holding (won't return on failure)
2581 */
2582 supR3HardenedMainDropPrivileges();
2583#endif
2584
2585 /*
2586 * Purge any environment variables and command line arguments considered harmful.
2587 */
2588 /** @todo May need to move this to a much earlier stage on windows. */
2589 supR3HardenedMainPurgeEnvironment(envp);
2590 supR3HardenedMainPurgeArgs(argc, argv, &argc, &argv);
2591
2592 /*
2593 * Load the IPRT, hand the SUPLib part the open driver and
2594 * call RTR3InitEx.
2595 */
2596 SUP_DPRINTF(("SUPR3HardenedMain: Load Runtime...\n"));
2597 g_enmSupR3HardenedMainState = SUPR3HARDENEDMAINSTATE_INIT_RUNTIME;
2598 supR3HardenedMainInitRuntime(fFlags);
2599#ifdef RT_OS_WINDOWS
2600 supR3HardenedWinModifyDllSearchPath(fFlags, g_szSupLibHardenedAppBinPath);
2601#endif
2602
2603 /*
2604 * Load the DLL/SO/DYLIB containing the actual program
2605 * and pass control to it.
2606 */
2607 SUP_DPRINTF(("SUPR3HardenedMain: Load TrustedMain...\n"));
2608 g_enmSupR3HardenedMainState = SUPR3HARDENEDMAINSTATE_GET_TRUSTED_MAIN;
2609 PFNSUPTRUSTEDMAIN pfnTrustedMain = supR3HardenedMainGetTrustedMain(pszProgName, fFlags);
2610
2611 SUP_DPRINTF(("SUPR3HardenedMain: Calling TrustedMain (%p)...\n", pfnTrustedMain));
2612 g_enmSupR3HardenedMainState = SUPR3HARDENEDMAINSTATE_CALLED_TRUSTED_MAIN;
2613 return pfnTrustedMain(argc, argv, envp);
2614}
2615
Note: See TracBrowser for help on using the repository browser.

© 2025 Oracle Support Privacy / Do Not Sell My Info Terms of Use Trademark Policy Automated Access Etiquette