diff options
| author |  scroggo <scroggo@chromium.org> | 2016-06-03 09:36:53 -0700 |
|---|---|---|
| committer |  Commit bot <commit-bot@chromium.org> | 2016-06-03 09:36:53 -0700 |
| commit | 1915b0bab2b48cf8bf85dc49e76994b033f25450 (patch) | |
| tree | 6954f5695e694dc3022f0cf3f716a4c5ad7c0604 /third_party | |
| parent | 7b9eabb392902e6e8f4206ba8aa041524258fd0f (diff) | |
Fix undefined behavior in libpng
Check for a null source before calling memcpy.
BUG=skia:5390
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2040433002
Review-Url: https://codereview.chromium.org/2040433002
Diffstat (limited to 'third_party')
| -rw-r--r-- | third_party/libpng/README.google | 1 | ||||
| -rw-r--r-- | third_party/libpng/pngpread.c | 11 |
2 files changed, 12 insertions, 0 deletions
diff --git a/third_party/libpng/README.google b/third_party/libpng/README.google index 20f5d46992..1acc408cb1 100644 --- a/third_party/libpng/README.google +++ b/third_party/libpng/README.google @@ -9,3 +9,4 @@ Local Modifications: (2) Included Intel optimizations by running: "patch -i contrib/intel/intel_sse.patch -p1" (3) Removed files unused by Skia + (4) Fixed an undefined behavior bug (skbug.com/5390) diff --git a/third_party/libpng/pngpread.c b/third_party/libpng/pngpread.c index 0dc1e53c22..0266cbe43a 100644 --- a/third_party/libpng/pngpread.c +++ b/third_party/libpng/pngpread.c @@ -499,7 +499,18 @@ png_push_save_buffer(png_structrp png_ptr) png_error(png_ptr, "Insufficient memory for save_buffer"); } +#if 0 + // This is the code checked into libpng. Calling memcpy with a null + // source is undefined, even if count is 0, but libpng does not + // currently check for null or 0. The Skia fix is below. + // skbug.com/5390 memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); +#else + if (old_buffer) + memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + else if (png_ptr->save_buffer_size) + png_error(png_ptr, "save_buffer error"); +#endif png_free(png_ptr, old_buffer); png_ptr->save_buffer_max = new_max; } |