Fix GH-20582: Heap Buffer Overflow in iptcembed #20591
Open
+104
−28
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
If you can extend the file between the file size gathering (resulting in a buffer allocation), and reading / writing to the file you can trigger a TOC-TOU where you write out of bounds.
To solve this, add extra bound checks and make sure that write actions always fail when going out of bounds.
The easiest way to trigger this is via a pipe, which is used in the test, but it should be possible with a regular file and a quick race condition as well.