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chromium / chromium / src / 3a4922a8bff5719beeb731a39878047e258245d1
commit3a4922a8bff5719beeb731a39878047e258245d1[log] [tgz]
authorTiago Vignatti <tvignatti@igalia.com>Mon Sep 29 16:47:21 2025
committerChromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com>Mon Sep 29 16:47:21 2025
treeec50427daa859d621c783bc5521a211e6adf3a96
parentefa8ace1e8cbe6471a7e11a60e1f079c1a6e6711 [diff]
Fix signed-to-unsigned conversion bug in PDF text processing

This commit fixes a bug in PDFiumPage where char count of -1 was
incorrectly converted to 4294967295 instead of 0.

A clusterfuzz testcase exposed this vulnerability through a unique PDF
object corruption:

  /ProcSet [/PDF/Text/ImageC/Image/Image/Image/Image/Image/Image...
  → thousands of repeated /Image entries

which would lead to a crash:
  1. FPDFText_LoadPage() fails when parsing malformed structures, returns nullptr
  2. FPDFText_CountChars(nullptr), returns -1
  3. CalculateTextRuns() converts -1 to uint32_t, becomes 4294967295
     (not 0 as stated in the comment!)
  4. GetTextRunInfoAt() returns empty optional for invalid indices
  5. Calling .value() on empty optional, crash

Bug: 447520186
Change-Id: Ide75829d73002c32b3e6d360ce6183a62c75d7b6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6995201
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1522295}
1 file changed
tree: ec50427daa859d621c783bc5521a211e6adf3a96
  1. .gemini/
  2. .github/
  3. agents/
  4. android_webview/
  5. apps/
  6. ash/
  7. base/
  8. build/
  9. build_overrides/
  10. buildtools/
  11. cc/
  12. chrome/
  13. chromecast/
  14. chromeos/
  15. codelabs/
  16. components/
  17. content/
  18. crypto/
  19. dbus/
  20. device/
  21. docs/
  22. extensions/
  23. fuchsia_web/
  24. gin/
  25. google_apis/
  26. gpu/
  27. headless/
  28. infra/
  29. ios/
  30. ipc/
  31. media/
  32. mojo/
  33. net/
  34. pdf/
  35. printing/
  36. remoting/
  37. rlz/
  38. sandbox/
  39. services/
  40. skia/
  41. sql/
  42. storage/
  43. styleguide/
  44. testing/
  45. third_party/
  46. tools/
  47. ui/
  48. url/
  49. webkit/
  50. clank
  51. clusterfuzz-data
  52. internal
  53. ios_internal
  54. signing_keys
  55. v8
  56. .clang-format
  57. .clang-tidy
  58. .clangd
  59. .cursorignore
  60. .geminiignore
  61. .git-blame-ignore-revs
  62. .gitallowed
  63. .gitattributes
  64. .gitignore
  65. .gitmodules
  66. .gn
  67. .mailmap
  68. .rustfmt.toml
  69. .vpython3
  70. .yapfignore
  71. ATL_OWNERS
  72. AUTHORS
  73. BUILD.gn
  74. CODE_OF_CONDUCT.md
  75. codereview.settings
  76. CPPLINT.cfg
  77. CRYPTO_OWNERS
  78. DEPS
  79. DIR_METADATA
  80. LICENSE
  81. LICENSE.chromium_os
  82. OWNERS
  83. PRESUBMIT.py
  84. PRESUBMIT_test.py
  85. PRESUBMIT_test_mocks.py
  86. README.md
  87. SECURITY_OWNERS
  88. WATCHLISTS
README.md

Logo Chromium

Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all users to experience the web.

The project's web site is https://www.chromium.org.

To check out the source code locally, don't use git clone! Instead, follow the instructions on how to get the code.

Documentation in the source is rooted in docs/README.md.

Learn how to Get Around the Chromium Source Code Directory Structure.

For historical reasons, there are some small top level directories. Now the guidance is that new top level directories are for product (e.g. Chrome, Android WebView, Ash). Even if these products have multiple executables, the code should be in subdirectories of the product.

If you found a bug, please file it at https://crbug.com/new.