diff options
Diffstat (limited to 'llvm/lib/Object/MachOObjectFile.cpp')
| -rw-r--r-- | llvm/lib/Object/MachOObjectFile.cpp | 55 |
1 files changed, 50 insertions, 5 deletions
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp index 43e76a9b404..26fd9a68724 100644 --- a/llvm/lib/Object/MachOObjectFile.cpp +++ b/llvm/lib/Object/MachOObjectFile.cpp @@ -328,6 +328,55 @@ static Error parseSegmentLoadCommand( return Error::success(); } +static Error checkSymtabCommand(const MachOObjectFile *Obj, + const MachOObjectFile::LoadCommandInfo &Load, + uint32_t LoadCommandIndex, + const char **SymtabLoadCmd) { + if (Load.C.cmdsize < sizeof(MachO::symtab_command)) + return malformedError("load command " + Twine(LoadCommandIndex) + + " LC_SYMTAB cmdsize too small"); + if (*SymtabLoadCmd != nullptr) + return malformedError("more than one LC_SYMTAB command"); + MachO::symtab_command Symtab = + getStruct<MachO::symtab_command>(Obj, Load.Ptr); + if (Symtab.cmdsize != sizeof(MachO::symtab_command)) + return malformedError("LC_SYMTAB command " + Twine(LoadCommandIndex) + + " has incorrect cmdsize"); + uint64_t FileSize = Obj->getData().size(); + if (Symtab.symoff > FileSize) + return malformedError("symoff field of LC_SYMTAB command " + + Twine(LoadCommandIndex) + " extends past the end " + "of the file"); + uint64_t BigSize = Symtab.nsyms; + const char *struct_nlist_name; + if (Obj->is64Bit()) { + BigSize *= sizeof(MachO::nlist_64); + struct_nlist_name = "struct nlist_64"; + } else { + BigSize *= sizeof(MachO::nlist); + struct_nlist_name = "struct nlist"; + } + BigSize += Symtab.symoff; + if (BigSize > FileSize) + return malformedError("symoff field plus nsyms field times sizeof(" + + Twine(struct_nlist_name) + ") of LC_SYMTAB command " + + Twine(LoadCommandIndex) + " extends past the end " + "of the file"); + if (Symtab.stroff > FileSize) + return malformedError("stroff field of LC_SYMTAB command " + + Twine(LoadCommandIndex) + " extends past the end " + "of the file"); + BigSize = Symtab.stroff; + BigSize += Symtab.strsize; + if (BigSize > FileSize) + return malformedError("stroff field plus strsize field of LC_SYMTAB " + "command " + Twine(LoadCommandIndex) + " extends " + "past the end of the file"); + + *SymtabLoadCmd = Load.Ptr; + return Error::success(); +} + Expected<std::unique_ptr<MachOObjectFile>> MachOObjectFile::create(MemoryBufferRef Object, bool IsLittleEndian, bool Is64Bits) { @@ -398,12 +447,8 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian, } LoadCommands.push_back(Load); if (Load.C.cmd == MachO::LC_SYMTAB) { - // Multiple symbol tables - if (SymtabLoadCmd) { - Err = malformedError("Multiple symbol tables"); + if ((Err = checkSymtabCommand(this, Load, I, &SymtabLoadCmd))) return; - } - SymtabLoadCmd = Load.Ptr; } else if (Load.C.cmd == MachO::LC_DYSYMTAB) { // Multiple dynamic symbol tables if (DysymtabLoadCmd) { |
