Next set of additional error checks for invalid Mach-O files for the
other load commands that use the MachO::dylinker_command type
but not used in llvm libObject code but used in llvm tool code.
This includes LC_ID_DYLINKER, LC_LOAD_DYLINKER
and LC_DYLD_ENVIRONMENT load commands.
llvm-svn: 282553
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index 8fa4cd4..fa00561 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -625,6 +625,35 @@
return Error::success();
}
+static Error checkDyldCommand(const MachOObjectFile *Obj,
+ const MachOObjectFile::LoadCommandInfo &Load,
+ uint32_t LoadCommandIndex, const char *CmdName) {
+ if (Load.C.cmdsize < sizeof(MachO::dylinker_command))
+ return malformedError("load command " + Twine(LoadCommandIndex) + " " +
+ CmdName + " cmdsize too small");
+ MachO::dylinker_command D = getStruct<MachO::dylinker_command>(Obj, Load.Ptr);
+ if (D.name < sizeof(MachO::dylinker_command))
+ return malformedError("load command " + Twine(LoadCommandIndex) + " " +
+ CmdName + " name.offset field too small, not past "
+ "the end of the dylinker_command struct");
+ if (D.name >= D.cmdsize)
+ return malformedError("load command " + Twine(LoadCommandIndex) + " " +
+ CmdName + " name.offset field extends past the end "
+ "of the load command");
+ // Make sure there is a null between the starting offset of the name and
+ // the end of the load command.
+ uint32_t i;
+ const char *P = (const char *)Load.Ptr;
+ for (i = D.name; i < D.cmdsize; i++)
+ if (P[i] == '\0')
+ break;
+ if (i >= D.cmdsize)
+ return malformedError("load command " + Twine(LoadCommandIndex) + " " +
+ CmdName + " dyld name extends past the end of the "
+ "load command");
+ return Error::success();
+}
+
Expected<std::unique_ptr<MachOObjectFile>>
MachOObjectFile::create(MemoryBufferRef Object, bool IsLittleEndian,
bool Is64Bits) {
@@ -777,6 +806,15 @@
if ((Err = checkDylibCommand(this, Load, I, "LC_LOAD_UPWARD_DYLIB")))
return;
Libraries.push_back(Load.Ptr);
+ } else if (Load.C.cmd == MachO::LC_ID_DYLINKER) {
+ if ((Err = checkDyldCommand(this, Load, I, "LC_ID_DYLINKER")))
+ return;
+ } else if (Load.C.cmd == MachO::LC_LOAD_DYLINKER) {
+ if ((Err = checkDyldCommand(this, Load, I, "LC_LOAD_DYLINKER")))
+ return;
+ } else if (Load.C.cmd == MachO::LC_DYLD_ENVIRONMENT) {
+ if ((Err = checkDyldCommand(this, Load, I, "LC_DYLD_ENVIRONMENT")))
+ return;
}
if (I < LoadCommandCount - 1) {
if (auto LoadOrErr = getNextLoadCommandInfo(this, I, Load))