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| author | Dan Sinclair <dsinclair@chromium.org> | 2017-01-03 14:57:14 -0500 |
|---|---|---|
| committer | Chromium commit bot <commit-bot@chromium.org> | 2017-01-03 21:07:51 +0000 |
| commit | 5e3b976529f18deb389ed608da88b895eb115d72 (patch) | |
| tree | b5c37c4957fc053d677ec75a021f95e3a3c3afdf | |
| parent | fa07af3e9b8fe849c973dd62f718ebb6bb4017c7 (diff) | |
| download | pdfium-5e3b976529f18deb389ed608da88b895eb115d72.tar.xz | |
Check for overflow in JBig2 Huffman decoder
This CL updates the Huffman decoder in the JBig2 codex to check the low field
does not overflow.
BUG=chromium:675236
Change-Id: I7f5f6fe8329df4ece6f317fac521fe2373686479
Reviewed-on: https://pdfium-review.googlesource.com/2131
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
| -rw-r--r-- | core/fxcodec/jbig2/JBig2_HuffmanTable.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/core/fxcodec/jbig2/JBig2_HuffmanTable.cpp b/core/fxcodec/jbig2/JBig2_HuffmanTable.cpp index 26f0e52310..baf97567fb 100644 --- a/core/fxcodec/jbig2/JBig2_HuffmanTable.cpp +++ b/core/fxcodec/jbig2/JBig2_HuffmanTable.cpp @@ -13,6 +13,7 @@ #include "core/fxcodec/jbig2/JBig2_Define.h" #include "core/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h" #include "core/fxcrt/fx_memory.h" +#include "third_party/base/numerics/safe_math.h" CJBig2_HuffmanTable::CJBig2_HuffmanTable(const JBig2TableLine* pTable, uint32_t nLines, @@ -61,17 +62,19 @@ bool CJBig2_HuffmanTable::ParseFromCodedBuffer(CJBig2_BitStream* pStream) { return false; ExtendBuffers(false); - int cur_low = low; + pdfium::base::CheckedNumeric<int> cur_low = low; do { if ((pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) || (pStream->readNBits(HTRS, &RANGELEN[NTEMP]) == -1) || (static_cast<size_t>(RANGELEN[NTEMP]) >= 8 * sizeof(cur_low))) { return false; } - RANGELOW[NTEMP] = cur_low; + RANGELOW[NTEMP] = cur_low.ValueOrDie(); cur_low += (1 << RANGELEN[NTEMP]); + if (!cur_low.IsValid()) + return false; ExtendBuffers(true); - } while (cur_low < high); + } while (cur_low.ValueOrDie() < high); if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) return false; |