diff options
author | Vedant Kumar <vsk@apple.com> | 2017-10-23 18:04:34 +0000 |
---|---|---|
committer | Vedant Kumar <vsk@apple.com> | 2017-10-23 18:04:34 +0000 |
commit | f9ce75bf1830d5488211ede06be71d08c694dcf3 (patch) | |
tree | 86ae4e7be4869a49d38d0b7029d8d16d527b0866 /lib/Object | |
parent | 3e1218f32a495fcfcded23b167f9d39cb01b0655 (diff) |
[wasm] readSection: Avoid reading past eof (fixes oss-fuzz #3219)
A wasm file crafted with a bogus section size can trigger an ASan issue
in the DWARFObjInMemory constructor. Nip the problem in the bud when we
read the wasm section.
Found by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3219
Differential Revision: https://reviews.llvm.org/D38777
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316357 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Object')
-rw-r--r-- | lib/Object/WasmObjectFile.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/Object/WasmObjectFile.cpp b/lib/Object/WasmObjectFile.cpp index 15a78df5402..86ce9c2209c 100644 --- a/lib/Object/WasmObjectFile.cpp +++ b/lib/Object/WasmObjectFile.cpp @@ -178,14 +178,16 @@ static wasm::WasmTable readTable(const uint8_t *&Ptr) { } static Error readSection(WasmSection &Section, const uint8_t *&Ptr, - const uint8_t *Start) { - // TODO(sbc): Avoid reading past EOF in the case of malformed files. + const uint8_t *Start, const uint8_t *Eof) { Section.Offset = Ptr - Start; Section.Type = readVaruint7(Ptr); uint32_t Size = readVaruint32(Ptr); if (Size == 0) return make_error<StringError>("Zero length section", object_error::parse_failed); + if (Ptr + Size > Eof) + return make_error<StringError>("Section too large", + object_error::parse_failed); Section.Content = ArrayRef<uint8_t>(Ptr, Size); Ptr += Size; return Error::success(); @@ -221,7 +223,7 @@ WasmObjectFile::WasmObjectFile(MemoryBufferRef Buffer, Error &Err) WasmSection Sec; while (Ptr < Eof) { - if ((Err = readSection(Sec, Ptr, getPtr(0)))) + if ((Err = readSection(Sec, Ptr, getPtr(0), Eof))) return; if ((Err = parseSection(Sec))) return; |