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authorChris Palmer <palmer@google.com>2014-07-18 15:18:43 -0700
committerChris Palmer <palmer@google.com>2014-07-18 15:18:43 -0700
commit98a44a176d137083434587fb5ebc53c6d963ff7f (patch)
treebb276e4674360135ba9eda2c6299b00f6dfb5bc8 /core/src/fpdfapi/fpdf_parser
parent5ffacd677a141ed2756009b0f4a07ee4cf284a1b (diff)
downloadpdfium-98a44a176d137083434587fb5ebc53c6d963ff7f.tar.xz
Fix the potential integer overflow from "offset + size".
BUG=382667 R=jschuh@chromium.org, jun_fang@foxitsoftware.com Review URL: https://codereview.chromium.org/390983007
Diffstat (limited to 'core/src/fpdfapi/fpdf_parser')
-rw-r--r--core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp24
1 files changed, 19 insertions, 5 deletions
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index f82bf3a861..14597d989c 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -2864,13 +2864,27 @@ FX_BOOL CPDF_DataAvail::IsObjectsAvail(CFX_PtrArray& obj_array, FX_BOOL bParsePa
CPDF_Reference *pRef = (CPDF_Reference*)pObj;
FX_DWORD dwNum = pRef->GetRefObjNum();
FX_FILESIZE offset;
- FX_DWORD size = GetObjectSize(pRef->GetRefObjNum(), offset);
- if (!size) {
+ FX_DWORD original_size = GetObjectSize(dwNum, offset);
+ base::CheckedNumeric<FX_DWORD> size = original_size;
+ if (size.ValueOrDefault(0) == 0 || offset < 0 || offset >= m_dwFileLen) {
break;
}
- size = (FX_DWORD)((FX_FILESIZE)(offset + size + 512) > m_dwFileLen ? m_dwFileLen - offset : size + 512);
- if (!m_pFileAvail->IsDataAvail(offset, size)) {
- pHints->AddSegment(offset, size);
+
+ size += offset;
+ size += 512;
+ if (!size.IsValid()) {
+ break;
+ }
+ if (size.ValueOrDie() > m_dwFileLen) {
+ size = m_dwFileLen - offset;
+ } else {
+ size = original_size + 512;
+ }
+ if (!size.IsValid()) {
+ break;
+ }
+ if (!m_pFileAvail->IsDataAvail(offset, size.ValueOrDie())) {
+ pHints->AddSegment(offset, size.ValueOrDie());
ret_array.Add(pObj);
count++;
} else if (!m_objnum_array.Find(dwNum)) {