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author | Tom Sepez <tsepez@chromium.org> | 2021-12-16 23:53:35 +0000 |
---|---|---|
committer | Michael BrĂ¼ning <michael.bruning@qt.io> | 2022-02-18 01:12:53 +0000 |
commit | c9b40289c5069cd340e2923c808eb22c89d8f6e5 (patch) | |
tree | 848c8b4c810a8f9e039acf1f03722446d0072ea5 | |
parent | 52c8c403c24b64c332d3ef48d4e2c7d5fecd4516 (diff) | |
download | qtwebengine-chromium-c9b40289c5069cd340e2923c808eb22c89d8f6e5.tar.gz |
[Backport] Security bug 1280743
Cherry-pick of patch originally reviewed on
https://pdfium-review.googlesource.com/c/pdfium/+/88290:
Use safe arithmetic in CJBig2_Context::ParseSymbolDict()
These should be mitigated by size checks higher up, but it wouldn't
hurt to be sure.
Bug: chromium:1280743
Change-Id: I03c46e3d11316a9f9634256bd0e2394548d2681e
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Michal Klocek <michal.klocek@qt.io>
-rw-r--r-- | chromium/third_party/pdfium/core/fxcodec/jbig2/JBig2_Context.cpp | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/chromium/third_party/pdfium/core/fxcodec/jbig2/JBig2_Context.cpp b/chromium/third_party/pdfium/core/fxcodec/jbig2/JBig2_Context.cpp index 8eab1dc6bef..117f707ee9b 100644 --- a/chromium/third_party/pdfium/core/fxcodec/jbig2/JBig2_Context.cpp +++ b/chromium/third_party/pdfium/core/fxcodec/jbig2/JBig2_Context.cpp @@ -409,28 +409,31 @@ JBig2_Result CJBig2_Context::ParseSymbolDict(CJBig2_Segment* pSegment) { return JBig2_Result::kFailure; } CJBig2_Segment* pLRSeg = nullptr; - pSymbolDictDecoder->SDNUMINSYMS = 0; + FX_SAFE_UINT32 dwNumSyms = 0; for (int32_t i = 0; i < pSegment->m_nReferred_to_segment_count; ++i) { CJBig2_Segment* pSeg = FindSegmentByNumber(pSegment->m_Referred_to_segment_numbers[i]); if (pSeg->m_cFlags.s.type == 0) { - pSymbolDictDecoder->SDNUMINSYMS += pSeg->m_SymbolDict->NumImages(); + dwNumSyms += pSeg->m_SymbolDict->NumImages(); pLRSeg = pSeg; } } + pSymbolDictDecoder->SDNUMINSYMS = dwNumSyms.ValueOrDie(); std::unique_ptr<CJBig2_Image*, FxFreeDeleter> SDINSYMS; if (pSymbolDictDecoder->SDNUMINSYMS != 0) { SDINSYMS.reset(FX_Alloc(CJBig2_Image*, pSymbolDictDecoder->SDNUMINSYMS)); - uint32_t dwTemp = 0; + dwNumSyms = 0; for (int32_t i = 0; i < pSegment->m_nReferred_to_segment_count; ++i) { CJBig2_Segment* pSeg = FindSegmentByNumber(pSegment->m_Referred_to_segment_numbers[i]); if (pSeg->m_cFlags.s.type == 0) { const CJBig2_SymbolDict& dict = *pSeg->m_SymbolDict; - for (size_t j = 0; j < dict.NumImages(); ++j) - SDINSYMS.get()[dwTemp + j] = dict.GetImage(j); - dwTemp += dict.NumImages(); + for (uint32_t j = 0; j < dict.NumImages(); ++j) { + uint32_t dwTemp = (dwNumSyms + j).ValueOrDie(); + SDINSYMS.get()[dwTemp] = dict.GetImage(j); + } + dwNumSyms += dict.NumImages(); } } } @@ -624,27 +627,30 @@ JBig2_Result CJBig2_Context::ParseTextRegion(CJBig2_Segment* pSegment) { return JBig2_Result::kFailure; } - pTRD->SBNUMSYMS = 0; + FX_SAFE_UINT32 dwNumSyms = 0; for (int32_t i = 0; i < pSegment->m_nReferred_to_segment_count; ++i) { CJBig2_Segment* pSeg = FindSegmentByNumber(pSegment->m_Referred_to_segment_numbers[i]); if (pSeg->m_cFlags.s.type == 0) { - pTRD->SBNUMSYMS += pSeg->m_SymbolDict->NumImages(); + dwNumSyms += pSeg->m_SymbolDict->NumImages(); } } + pTRD->SBNUMSYMS = dwNumSyms.ValueOrDie(); std::unique_ptr<CJBig2_Image*, FxFreeDeleter> SBSYMS; if (pTRD->SBNUMSYMS > 0) { SBSYMS.reset(FX_Alloc(CJBig2_Image*, pTRD->SBNUMSYMS)); - dwTemp = 0; + dwNumSyms = 0; for (int32_t i = 0; i < pSegment->m_nReferred_to_segment_count; ++i) { CJBig2_Segment* pSeg = FindSegmentByNumber(pSegment->m_Referred_to_segment_numbers[i]); if (pSeg->m_cFlags.s.type == 0) { const CJBig2_SymbolDict& dict = *pSeg->m_SymbolDict; - for (size_t j = 0; j < dict.NumImages(); ++j) - SBSYMS.get()[dwTemp + j] = dict.GetImage(j); - dwTemp += dict.NumImages(); + for (uint32_t j = 0; j < dict.NumImages(); ++j) { + uint32_t dwIndex = (dwNumSyms + j).ValueOrDie(); + SBSYMS.get()[dwIndex] = dict.GetImage(j); + } + dwNumSyms += dict.NumImages(); } } pTRD->SBSYMS = SBSYMS.get(); |