diff options
| -rw-r--r-- | chromium/third_party/pdfium/core/fpdfapi/parser/cpdf_document.cpp | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/chromium/third_party/pdfium/core/fpdfapi/parser/cpdf_document.cpp b/chromium/third_party/pdfium/core/fpdfapi/parser/cpdf_document.cpp index 44fa2a1009e..8179db37a3b 100644 --- a/chromium/third_party/pdfium/core/fpdfapi/parser/cpdf_document.cpp +++ b/chromium/third_party/pdfium/core/fpdfapi/parser/cpdf_document.cpp @@ -20,6 +20,7 @@ #include "core/fxcrt/fx_codepage.h" #include "core/fxcrt/scoped_set_insertion.h" #include "core/fxcrt/stl_util.h" +#include "third_party/abseil-cpp/absl/types/optional.h" #include "third_party/base/check.h" #include "third_party/base/containers/contains.h" @@ -27,7 +28,9 @@ namespace { const int kMaxPageLevel = 1024; -int CountPages(CPDF_Dictionary* pPages, +// Returns a value in the range [0, `CPDF_Document::kPageMaxNum`), or nullopt on +// error. +absl::optional<int> CountPages(CPDF_Dictionary* pPages, std::set<CPDF_Dictionary*>* visited_pages) { int count = pPages->GetIntegerFor("Count"); if (count > 0 && count < CPDF_Document::kPageMaxNum) @@ -43,11 +46,19 @@ int CountPages(CPDF_Dictionary* pPages, if (pKid->KeyExist("Kids")) { // Use |visited_pages| to help detect circular references of pages. ScopedSetInsertion<CPDF_Dictionary*> local_add(visited_pages, pKid); - count += CountPages(pKid, visited_pages); + absl::optional<int> local_count = + CountPages(pKid, visited_pages); + if (!local_count.has_value()) { + return absl::nullopt; // Propagate error. + } + count += local_count.value(); } else { // This page is a leaf node. count++; } + if (count >= CPDF_Document::kPageMaxNum) { + return absl::nullopt; // Error: too many pages. + } } pPages->SetNewFor<CPDF_Number>("Count", count); return count; @@ -366,7 +377,7 @@ int CPDF_Document::RetrievePageCount() { std::set<CPDF_Dictionary*> visited_pages; visited_pages.insert(pPages); - return CountPages(pPages, &visited_pages); + return CountPages(pPages, &visited_pages).value_or(0); } uint32_t CPDF_Document::GetUserPermissions() const { |