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Diffstat (limited to 'src/VBox/HostDrivers/Support/posix/SUPR3HardenedMain-posix.cpp')
| -rw-r--r-- | src/VBox/HostDrivers/Support/posix/SUPR3HardenedMain-posix.cpp | 708 |
1 files changed, 708 insertions, 0 deletions
diff --git a/src/VBox/HostDrivers/Support/posix/SUPR3HardenedMain-posix.cpp b/src/VBox/HostDrivers/Support/posix/SUPR3HardenedMain-posix.cpp new file mode 100644 index 00000000..fe55c4da --- /dev/null +++ b/src/VBox/HostDrivers/Support/posix/SUPR3HardenedMain-posix.cpp @@ -0,0 +1,708 @@ +/* $Id: SUPR3HardenedMain-posix.cpp $ */ +/** @file + * VirtualBox Support Library - Hardened main(), posix bits. + */ + +/* + * Copyright (C) 2017-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <VBox/err.h> +#include <VBox/dis.h> +#include <VBox/sup.h> + +#include <iprt/path.h> +#include <iprt/string.h> +#include <iprt/x86.h> + +#include <dlfcn.h> +#include <sys/mman.h> +#if defined(RT_OS_SOLARIS) +# include <link.h> +#endif +#include <stdio.h> +#include <stdint.h> + +#include "SUPLibInternal.h" + + +/********************************************************************************************************************************* +* Defined Constants And Macros * +*********************************************************************************************************************************/ + +/** + * Memory for code patching. + */ +#define DLOPEN_PATCH_MEMORY_SIZE _4K + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +#ifndef SUP_HARDENED_WITHOUT_DLOPEN_PATCHING +/** + * Callback (SUPHARDENEDPOSIXHOOK::pfnResolv) for triggering lazy GOT resolver. + * + * This generally just calls the API in a harmless manner and triggers the lazy + * resolving of the symbol, ensuring a proper address in the GOT/PLT entry. + * + * On Solaris dlsym() will return the value in the GOT/PLT entry. We don't wish + * to patch the lazy loader trampoline function, but rather the real function! + */ +typedef DECLCALLBACKTYPE(void, FNSUPHARDENEDSYMRESOLVE,(void)); +/** Pointer to FNSUPHARDENEDSYMRESOLVE. */ +typedef FNSUPHARDENEDSYMRESOLVE *PFNSUPHARDENEDSYMRESOLVE; + +/** + * A hook descriptor. + */ +typedef struct SUPHARDENEDPOSIXHOOK +{ + /** The symbol to hook. */ + const char *pszSymbol; + /** The intercepting wrapper doing additional checks. */ + PFNRT pfnHook; + /** Where to store the pointer to the code into patch memory + * which resumes the original call. + * @note uintptr_t instead of PFNRT is for Clang 11. */ + uintptr_t *ppfnRealResume; + /** Pointer to the resolver method used on Solaris. */ + PFNSUPHARDENEDSYMRESOLVE pfnResolve; +} SUPHARDENEDPOSIXHOOK; +/** Pointer to a hook descriptor. */ +typedef SUPHARDENEDPOSIXHOOK *PSUPHARDENEDPOSIXHOOK; +/** Pointer to a const hook descriptor. */ +typedef const SUPHARDENEDPOSIXHOOK *PCSUPHARDENEDPOSIXHOOK; + +/** dlopen() declaration. */ +typedef void *FNDLOPEN(const char *pszFilename, int fFlags); +/** Pointer to dlopen. */ +typedef FNDLOPEN *PFNDLOPEN; + +#ifdef SUP_HARDENED_WITH_DLMOPEN +/** dlmopen() declaration */ +typedef void *FNDLMOPEN(Lmid_t idLm, const char *pszFilename, int fFlags); +/** Pointer to dlmopen. */ +typedef FNDLMOPEN *PFNDLMOPEN; +#endif + +#endif /* SUP_HARDENED_WITHOUT_DLOPEN_PATCHING */ + + +/********************************************************************************************************************************* +* Internal Functions * +*********************************************************************************************************************************/ +#ifndef SUP_HARDENED_WITHOUT_DLOPEN_PATCHING +static FNSUPHARDENEDSYMRESOLVE supR3HardenedPosixMonitorDlopenResolve; +#ifdef SUP_HARDENED_WITH_DLMOPEN +static FNSUPHARDENEDSYMRESOLVE supR3HardenedPosixMonitorDlmopenResolve; +#endif + +/* SUPR3HardenedMainA-posix.asm: */ +DECLASM(void) supR3HardenedPosixMonitor_Dlopen(const char *pszFilename, int fFlags); +#ifdef SUP_HARDENED_WITH_DLMOPEN +DECLASM(void) supR3HardenedPosixMonitor_Dlmopen(Lmid_t idLm, const char *pszFilename, int fFlags); +#endif +#endif /* SUP_HARDENED_WITHOUT_DLOPEN_PATCHING */ + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +#ifndef SUP_HARDENED_WITHOUT_DLOPEN_PATCHING + +RT_C_DECLS_BEGIN +/** Resume patch for dlopen(), jumped to form assembly stub. */ +DECL_HIDDEN_DATA(PFNDLOPEN) g_pfnDlopenReal = NULL; +#ifdef SUP_HARDENED_WITH_DLMOPEN +/** Resume patch for dlmopen(), jumped to form assembly stub. */ +DECL_HIDDEN_DATA(PFNDLMOPEN) g_pfnDlmopenReal = NULL; +#endif +RT_C_DECLS_END + +/** Memory allocated for the patches. */ +static uint8_t *g_pbExecMemory = NULL; +/** Offset into the patch memory which is not used. */ +static uint32_t g_offExecMemory = 0; + +/** + * Array of hooks to install. + */ +static SUPHARDENEDPOSIXHOOK const g_aHooks[] = +{ + /* pszSymbol, pfnHook, ppfnRealResume, pfnResolve */ + { "dlopen", (PFNRT)supR3HardenedPosixMonitor_Dlopen, (uintptr_t *)&g_pfnDlopenReal, supR3HardenedPosixMonitorDlopenResolve }, +#ifdef SUP_HARDENED_WITH_DLMOPEN + { "dlmopen", (PFNRT)supR3HardenedPosixMonitor_Dlmopen, (uintptr_t *)&g_pfnDlmopenReal, supR3HardenedPosixMonitorDlmopenResolve } +#endif +}; + + + +/** + * Verifies the given library for proper access rights for further loading + * into the process. + * + * @returns Flag whether the access rights of the library look sane and loading + * it is not considered a security risk. Returns true if the library + * looks sane, false otherwise. + * @param pszFilename The library to load, this can be an absolute or relative path + * or just the filename of the library when the default paths should + * be searched. NULL is allowed too to indicate opening the main + * binary. + */ +DECLASM(bool) supR3HardenedPosixMonitor_VerifyLibrary(const char *pszFilename) +{ + /* + * Giving NULL as the filename indicates opening the main program which is fine + * We are already loaded and executing after all. + * + * Filenames without any path component (whether absolute or relative) are allowed + * unconditionally too as the loader will only search the default paths configured by root. + */ + bool fAllow = true; + + if ( pszFilename + && strchr(pszFilename, '/') != NULL) + { +#if defined(RT_OS_LINUX) + int rc = supR3HardenedVerifyFileFollowSymlinks(pszFilename, RTHCUINTPTR_MAX, true /* fMaybe3rdParty */, + NULL /* pErrInfo */); +#else + int rc = supR3HardenedVerifyFile(pszFilename, RTHCUINTPTR_MAX, true /* fMaybe3rdParty */, + NULL /* pErrInfo */); +#endif + + if (RT_FAILURE(rc)) + fAllow = false; + } + + return fAllow; +} + + +/** + * Returns the start address of the given symbol if found or NULL otherwise. + * + * @returns Start address of the symbol or NULL if not found. + * @param pszSymbol The symbol name. + * @param pfnResolve The resolver to call before trying to query the start address. + */ +static void *supR3HardenedMainPosixGetStartBySymbol(const char *pszSymbol, PFNSUPHARDENEDSYMRESOLVE pfnResolve) +{ +#ifndef RT_OS_SOLARIS + RT_NOREF(pfnResolve); + return dlsym(RTLD_DEFAULT, pszSymbol); + +#else /* RT_OS_SOLARIS */ + /* + * Solaris is tricky as dlsym doesn't return the actual start address of + * the symbol but the start of the trampoline in the PLT of the caller. + * + * Disassemble the first jmp instruction to get at the entry in the global + * offset table where the actual address is stored. + * + * To counter lazy symbol resolving, we first have to call the API before + * trying to resolve and disassemble it. + */ + pfnResolve(); + + uint8_t *pbSym = (uint8_t *)dlsym(RTLD_DEFAULT, pszSymbol); + +# ifdef RT_ARCH_AMD64 + DISSTATE Dis; + uint32_t cbInstr = 1; + int rc = DISInstr(pbSym, DISCPUMODE_64BIT, &Dis, &cbInstr); + if ( RT_FAILURE(rc) + || Dis.pCurInstr->uOpcode != OP_JMP + || !(Dis.ModRM.Bits.Mod == 0 && Dis.ModRM.Bits.Rm == 5 /* wrt RIP */)) + return NULL; + + /* Extract start address. */ + pbSym = (pbSym + cbInstr + Dis.Param1.uDisp.i32); + pbSym = (uint8_t *)*((uintptr_t *)pbSym); +# else +# error "Unsupported architecture" +# endif + + return pbSym; +#endif /* RT_OS_SOLARIS */ +} + + +/** + * Allocates executable patch memory with the given constraints. + * + * @returns VBox status code. + * @param cb Size of the patch memory in bytes. + * @param pvHint Where to try allocating nearby. + * @param fRipRelAddr Flag whether the executable memory must be within + * 2GB before or after the hint as it will contain + * instructions using RIP relative addressing + */ +static uint8_t *supR3HardenedMainPosixExecMemAlloc(size_t cb, void *pvHint, bool fRipRelAddr) +{ + AssertReturn(cb < _1K, NULL); + + /* Lazy allocation of exectuable memory. */ + if (!g_pbExecMemory) + { + g_pbExecMemory = (uint8_t *)mmap(pvHint, DLOPEN_PATCH_MEMORY_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); + g_offExecMemory = 0; + if (g_pbExecMemory == MAP_FAILED) + return NULL; + + memset(g_pbExecMemory, 0xcc, DLOPEN_PATCH_MEMORY_SIZE); + } + + if (g_offExecMemory + cb >= DLOPEN_PATCH_MEMORY_SIZE) + return NULL; + + uint8_t *pb = &g_pbExecMemory[g_offExecMemory]; + + if (fRipRelAddr) + { + /* Check that we allocated within 2GB of the hint. */ + uintptr_t uPtrHint = (uintptr_t)pvHint; + uintptr_t uPtrPatchMem = (uintptr_t)pb; + uintptr_t cbDistance = uPtrHint < uPtrPatchMem + ? uPtrPatchMem - uPtrHint + : uPtrHint - uPtrPatchMem; + + if (cbDistance >= _2G - _4K) + return NULL; + } + + g_offExecMemory = RT_ALIGN_32(g_offExecMemory + cb, 16); + return pb; +} + + +/** + * Hooks the given method to execute the given one first. + * + * @returns VBox status code. + * @param pszSymbol The symbol to hook. + * @param pfnHook The hook to install. + * @param ppfnReal Where to store the pointer to entry point of the real method + * (somewhere in patch memory). + * @param pfnResolve The resolver to call before trying to query the start address. + */ +static int supR3HardenedMainPosixHookOne(const char *pszSymbol, PFNRT pfnHook, uintptr_t /*PFNRT*/ *ppfnReal, + PFNSUPHARDENEDSYMRESOLVE pfnResolve) +{ + void *pfnTarget = supR3HardenedMainPosixGetStartBySymbol(pszSymbol, pfnResolve); + if (!pfnTarget) + return VERR_NOT_FOUND; + + /* + * Make the target memory writeable to be able to insert the patch. + * Unprotect two pages in case the code crosses a page boundary. + */ + void *pvTargetBase = (void *)(((uintptr_t)pfnTarget) & ~(uintptr_t)(_4K - 1)); + int rcPsx = mprotect(pvTargetBase, 2 * _4K, PROT_WRITE | PROT_READ | PROT_EXEC); + if (rcPsx == -1) + return VERR_SUPLIB_TEXT_NOT_WRITEABLE; + + uint8_t * const pbTarget = (uint8_t *)(uintptr_t)pfnTarget; + + DISSTATE Dis; + uint32_t cbInstr; + uint32_t offJmpBack = 0; + uint32_t cbPatchMem = 0; + +#ifdef RT_ARCH_AMD64 + /* + * Patch 64-bit hosts. + */ + uint32_t cRipRelMovs = 0; + uint32_t cRelCalls = 0; + + /* Just use the disassembler to skip 12 bytes or more, we might need to + rewrite mov instructions using RIP relative addressing. */ + while (offJmpBack < 12) + { + cbInstr = 1; + int rc = DISInstr(pbTarget + offJmpBack, DISCPUMODE_64BIT, &Dis, &cbInstr); + if ( RT_FAILURE(rc) + || ( Dis.pCurInstr->fOpType & DISOPTYPE_CONTROLFLOW + && Dis.pCurInstr->uOpcode != OP_CALL) + || ( Dis.ModRM.Bits.Mod == 0 + && Dis.ModRM.Bits.Rm == 5 /* wrt RIP */ + && Dis.pCurInstr->uOpcode != OP_MOV)) + return VERR_SUPLIB_UNEXPECTED_INSTRUCTION; + + if (Dis.ModRM.Bits.Mod == 0 && Dis.ModRM.Bits.Rm == 5 /* wrt RIP */) + cRipRelMovs++; + if ( Dis.pCurInstr->uOpcode == OP_CALL + && (Dis.pCurInstr->fOpType & DISOPTYPE_RELATIVE_CONTROLFLOW)) + cRelCalls++; + + offJmpBack += cbInstr; + cbPatchMem += cbInstr; + } + + /* + * Each relative call requires extra bytes as it is converted to a pushq imm32 + * + mov [RSP+4], imm32 + a jmp qword [$+8 wrt RIP] to avoid clobbering registers. + */ + cbPatchMem += cRelCalls * RT_ALIGN_32(13 + 6 + 8, 8); + cbPatchMem += 14; /* jmp qword [$+8 wrt RIP] + 8 byte address to jump to. */ + cbPatchMem = RT_ALIGN_32(cbPatchMem, 8); + + /* Allocate suitable executable memory available. */ + bool fConvRipRelMovs = false; + uint8_t *pbPatchMem = supR3HardenedMainPosixExecMemAlloc(cbPatchMem, pbTarget, cRipRelMovs > 0); + if (!pbPatchMem) + { + /* + * Try to allocate memory again without the RIP relative mov addressing constraint + * Makes it a bit more difficult for us later on but there is no way around it. + * We need to increase the patch memory because we create two instructions for one + * (7 bytes for the RIP relative mov vs. 13 bytes for the two instructions replacing it -> + * need to allocate 6 bytes more per RIP relative mov). + */ + fConvRipRelMovs = true; + if (cRipRelMovs > 0) + pbPatchMem = supR3HardenedMainPosixExecMemAlloc(cbPatchMem + cRipRelMovs * 6, + pbTarget, false /*fRipRelAddr*/); + + if (!pbPatchMem) + return VERR_NO_MEMORY; + } + + /* Assemble the code for resuming the call.*/ + *ppfnReal = (uintptr_t)pbPatchMem; + + /* Go through the instructions to patch and fixup any rip relative mov instructions. */ + uint32_t offInsn = 0; + while (offInsn < offJmpBack) + { + cbInstr = 1; + int rc = DISInstr(pbTarget + offInsn, DISCPUMODE_64BIT, &Dis, &cbInstr); + if ( RT_FAILURE(rc) + || ( Dis.pCurInstr->fOpType & DISOPTYPE_CONTROLFLOW + && Dis.pCurInstr->uOpcode != OP_CALL)) + return VERR_SUPLIB_UNEXPECTED_INSTRUCTION; + + if ( Dis.ModRM.Bits.Mod == 0 + && Dis.ModRM.Bits.Rm == 5 /* wrt RIP */ + && Dis.pCurInstr->uOpcode == OP_MOV) + { + /* Deduce destination register and write out new instruction. */ + if (RT_UNLIKELY(!( (Dis.Param1.fUse & (DISUSE_BASE | DISUSE_REG_GEN64)) + && (Dis.Param2.fUse & DISUSE_RIPDISPLACEMENT32)))) + return VERR_SUPLIB_UNEXPECTED_INSTRUCTION; + + uintptr_t uAddr = (uintptr_t)&pbTarget[offInsn + cbInstr] + (intptr_t)Dis.Param2.uDisp.i32; + + if (fConvRipRelMovs) + { + /* + * Create two instructions, first one moves the address as a constant to the destination register + * and the second one loads the data from the memory into the destination register. + */ + + *pbPatchMem++ = 0x48; + *pbPatchMem++ = 0xb8 + Dis.Param1.Base.idxGenReg; + *(uintptr_t *)pbPatchMem = uAddr; + pbPatchMem += sizeof(uintptr_t); + + *pbPatchMem++ = 0x48; + *pbPatchMem++ = 0x8b; + *pbPatchMem++ = (Dis.Param1.Base.idxGenReg << X86_MODRM_REG_SHIFT) | Dis.Param1.Base.idxGenReg; + } + else + { + intptr_t iDispNew = uAddr - (uintptr_t)&pbPatchMem[3 + sizeof(int32_t)]; + Assert(iDispNew == (int32_t)iDispNew); + + /* Assemble the mov to register instruction with the updated rip relative displacement. */ + *pbPatchMem++ = 0x48; + *pbPatchMem++ = 0x8b; + *pbPatchMem++ = (Dis.Param1.Base.idxGenReg << X86_MODRM_REG_SHIFT) | 5; + *(int32_t *)pbPatchMem = (int32_t)iDispNew; + pbPatchMem += sizeof(int32_t); + } + } + else if ( Dis.pCurInstr->uOpcode == OP_CALL + && (Dis.pCurInstr->fOpType & DISOPTYPE_RELATIVE_CONTROLFLOW)) + { + /* Convert to absolute jump. */ + uintptr_t uAddr = (uintptr_t)&pbTarget[offInsn + cbInstr] + (intptr_t)Dis.Param1.uValue; + + /* Skip the push instructions till the return address is known. */ + uint8_t *pbPatchMemPush = pbPatchMem; + pbPatchMem += 13; + + *pbPatchMem++ = 0xff; /* jmp qword [$+8 wrt RIP] */ + *pbPatchMem++ = 0x25; + *(uint32_t *)pbPatchMem = (uint32_t)(RT_ALIGN_PT(pbPatchMem + 4, 8, uint8_t *) - (pbPatchMem + 4)); + pbPatchMem = RT_ALIGN_PT(pbPatchMem + 4, 8, uint8_t *); + *(uint64_t *)pbPatchMem = uAddr; + pbPatchMem += sizeof(uint64_t); + + /* Push the return address onto stack. Difficult on amd64 without clobbering registers... */ + uintptr_t uAddrReturn = (uintptr_t)pbPatchMem; + *pbPatchMemPush++ = 0x68; /* push imm32 sign-extended as 64-bit*/ + *(uint32_t *)pbPatchMemPush = RT_LO_U32(uAddrReturn); + pbPatchMemPush += sizeof(uint32_t); + *pbPatchMemPush++ = 0xc7; + *pbPatchMemPush++ = 0x44; + *pbPatchMemPush++ = 0x24; + *pbPatchMemPush++ = 0x04; /* movl [RSP+4], imm32 */ + *(uint32_t *)pbPatchMemPush = RT_HI_U32(uAddrReturn); + } + else + { + memcpy(pbPatchMem, pbTarget + offInsn, cbInstr); + pbPatchMem += cbInstr; + } + + offInsn += cbInstr; + } + + *pbPatchMem++ = 0xff; /* jmp qword [$+8 wrt RIP] */ + *pbPatchMem++ = 0x25; + *(uint32_t *)pbPatchMem = (uint32_t)(RT_ALIGN_PT(pbPatchMem + 4, 8, uint8_t *) - (pbPatchMem + 4)); + pbPatchMem = RT_ALIGN_PT(pbPatchMem + 4, 8, uint8_t *); + *(uint64_t *)pbPatchMem = (uintptr_t)&pbTarget[offJmpBack]; + + /* Assemble the patch. */ + Assert(offJmpBack >= 12); + pbTarget[0] = 0x48; /* mov rax, qword */ + pbTarget[1] = 0xb8; + *(uintptr_t *)&pbTarget[2] = (uintptr_t)pfnHook; + pbTarget[10] = 0xff; /* jmp rax */ + pbTarget[11] = 0xe0; + +#else /* !RT_ARCH_AMD64 */ + /* + * Patch 32-bit hosts. + */ + /* Just use the disassembler to skip 5 bytes or more. */ + while (offJmpBack < 5) + { + cbInstr = 1; + int rc = DISInstr(pbTarget + offJmpBack, DISCPUMODE_32BIT, &Dis, &cbInstr); + if ( RT_FAILURE(rc) + || ( (Dis.pCurInstr->fOpType & DISOPTYPE_CONTROLFLOW) + && Dis.pCurInstr->uOpcode != OP_CALL)) + return VERR_SUPLIB_UNEXPECTED_INSTRUCTION; + + if ( Dis.pCurInstr->uOpcode == OP_CALL + && (Dis.pCurInstr->fOpType & DISOPTYPE_RELATIVE_CONTROLFLOW)) + cbPatchMem += 10; /* push imm32 + jmp rel32 */ + else + cbPatchMem += cbInstr; + + offJmpBack += cbInstr; + } + + /* Allocate suitable exectuable memory available. */ + uint8_t *pbPatchMem = supR3HardenedMainPosixExecMemAlloc(cbPatchMem, pbTarget, false /* fRipRelAddr */); + if (!pbPatchMem) + return VERR_NO_MEMORY; + + /* Assemble the code for resuming the call.*/ + *ppfnReal = (uintptr_t)pbPatchMem; + + /* Go through the instructions to patch and fixup any relative call instructions. */ + uint32_t offInsn = 0; + while (offInsn < offJmpBack) + { + cbInstr = 1; + int rc = DISInstr(pbTarget + offInsn, DISCPUMODE_32BIT, &Dis, &cbInstr); + if ( RT_FAILURE(rc) + || ( (Dis.pCurInstr->fOpType & DISOPTYPE_CONTROLFLOW) + && Dis.pCurInstr->uOpcode != OP_CALL)) + return VERR_SUPLIB_UNEXPECTED_INSTRUCTION; + + if ( Dis.pCurInstr->uOpcode == OP_CALL + && (Dis.pCurInstr->fOpType & DISOPTYPE_RELATIVE_CONTROLFLOW)) + { + /* + * Don't use a call instruction directly but push the original return address + * onto the stack and use a relative jump to the call target. + * The reason here is that on Linux the called method saves the return + * address from the stack which will be different from the original because + * the code is executed from our patch memory. + * + * Luckily the call instruction is 5 bytes long which means it is always the + * last instruction to patch and we don't need to return from the call + * to patch memory anyway but can use this method to resume the original call. + */ + AssertReturn(offInsn + cbInstr >= offJmpBack, VERR_SUPLIB_UNEXPECTED_INSTRUCTION); /* Must be last instruction! */ + + /* push return address */ + uint32_t const uAddrReturn = (uintptr_t)&pbTarget[offInsn + cbInstr]; /* The return address to push to the stack. */ + + *pbPatchMem++ = 0x68; /* push dword */ + *(uint32_t *)pbPatchMem = uAddrReturn; + pbPatchMem += sizeof(uint32_t); + + /* jmp rel32 to the call target */ + uintptr_t const uAddr = uAddrReturn + (int32_t)Dis.Param1.uValue; + int32_t const i32DispNew = uAddr - (uintptr_t)&pbPatchMem[5]; + + *pbPatchMem++ = 0xe9; /* jmp rel32 */ + *(int32_t *)pbPatchMem = i32DispNew; + pbPatchMem += sizeof(int32_t); + } + else + { + memcpy(pbPatchMem, pbTarget + offInsn, cbInstr); + pbPatchMem += cbInstr; + } + + offInsn += cbInstr; + } + + *pbPatchMem++ = 0xe9; /* jmp rel32 */ + *(uint32_t *)pbPatchMem = (uintptr_t)&pbTarget[offJmpBack] - ((uintptr_t)pbPatchMem + 4); + + /* Assemble the patch. */ + Assert(offJmpBack >= 5); + pbTarget[0] = 0xe9; + *(uint32_t *)&pbTarget[1] = (uintptr_t)pfnHook - (uintptr_t)&pbTarget[1+4]; +#endif /* !RT_ARCH_AMD64 */ + + /* + * Re-seal target (ASSUMING that the shared object either has page aligned + * section or that the patch target is far enough from the writable parts). + */ + rcPsx = mprotect(pvTargetBase, 2 * _4K, PROT_READ | PROT_EXEC); + if (rcPsx == -1) + return VERR_SUPLIB_TEXT_NOT_SEALED; + + return VINF_SUCCESS; +} + + +/** + * @callback_method_impl{FNSUPHARDENEDSYMRESOLVE, dlopen} + */ +static DECLCALLBACK(void) supR3HardenedPosixMonitorDlopenResolve(void) +{ + /* Make harmless dlopen call. */ + void *pv = dlopen(NULL, RTLD_LAZY); + if (pv) + dlclose(pv); +} + + +#ifdef SUP_HARDENED_WITH_DLMOPEN +/** + * @callback_method_impl{FNSUPHARDENEDSYMRESOLVE, dlmopen} + */ +static DECLCALLBACK(void) supR3HardenedPosixMonitorDlmopenResolve(void) +{ + /* Make harmless dlmopen call. */ + void *pv = dlmopen(LM_ID_BASE, NULL, RTLD_LAZY); + if (pv) + dlclose(pv); +} +#endif + +#endif /* SUP_HARDENED_WITHOUT_DLOPEN_PATCHING */ + + +/** + * Hardening initialization for POSIX compatible hosts. + * + * @note Doesn't return on error. + */ +DECLHIDDEN(void) supR3HardenedPosixInit(void) +{ +#ifndef SUP_HARDENED_WITHOUT_DLOPEN_PATCHING + for (unsigned i = 0; i < RT_ELEMENTS(g_aHooks); i++) + { + PCSUPHARDENEDPOSIXHOOK pHook = &g_aHooks[i]; + int rc = supR3HardenedMainPosixHookOne(pHook->pszSymbol, pHook->pfnHook, pHook->ppfnRealResume, pHook->pfnResolve); + if (RT_FAILURE(rc)) + supR3HardenedFatalMsg("supR3HardenedPosixInit", kSupInitOp_Integrity, rc, + "Failed to hook the %s interface", pHook->pszSymbol); + } +#endif +} + + + +/* + * assert.cpp + * + * ASSUMES working DECLHIDDEN or there will be symbol confusion! + */ + +RTDATADECL(char) g_szRTAssertMsg1[1024]; +RTDATADECL(char) g_szRTAssertMsg2[4096]; +RTDATADECL(const char * volatile) g_pszRTAssertExpr; +RTDATADECL(const char * volatile) g_pszRTAssertFile; +RTDATADECL(uint32_t volatile) g_u32RTAssertLine; +RTDATADECL(const char * volatile) g_pszRTAssertFunction; + +RTDECL(bool) RTAssertMayPanic(void) +{ + return true; +} + + +RTDECL(void) RTAssertMsg1(const char *pszExpr, unsigned uLine, const char *pszFile, const char *pszFunction) +{ + /* + * Fill in the globals. + */ + g_pszRTAssertExpr = pszExpr; + g_pszRTAssertFile = pszFile; + g_pszRTAssertFunction = pszFunction; + g_u32RTAssertLine = uLine; + snprintf(g_szRTAssertMsg1, sizeof(g_szRTAssertMsg1), + "\n!!Assertion Failed!!\n" + "Expression: %s\n" + "Location : %s(%u) %s\n", + pszExpr, pszFile, uLine, pszFunction); +} + + +RTDECL(void) RTAssertMsg2V(const char *pszFormat, va_list va) +{ + vsnprintf(g_szRTAssertMsg2, sizeof(g_szRTAssertMsg2), pszFormat, va); + if (g_enmSupR3HardenedMainState < SUPR3HARDENEDMAINSTATE_CALLED_TRUSTED_MAIN) + supR3HardenedFatalMsg(g_pszRTAssertExpr, kSupInitOp_Misc, VERR_INTERNAL_ERROR, + "%s%s", g_szRTAssertMsg1, g_szRTAssertMsg2); + else + supR3HardenedError(VERR_INTERNAL_ERROR, false/*fFatal*/, "%s%s", g_szRTAssertMsg1, g_szRTAssertMsg2); +} + |