webp: Improve valid_file to check the header for magic words#5266
Merged
Conversation
This is MUCH faster than asking libwebp to open the file! Signed-off-by: Larry Gritz <lg@larrygritz.com>
Contributor
|
Here we are giving a 64byte header to WebpGetInfo to parse through. Is that so much slower than doing a 12byte read here? Is WebP going off the rails validating that 64bytes? |
Collaborator
Author
|
I found at least some cases where this kept webp from going off the rails. |
jessey-git
approved these changes
Jul 1, 2026
jessey-git
left a comment
jessey-git
left a comment
Contributor
There was a problem hiding this comment.
Sounds like an issue that would be interesting to file against libwebp. Extreme resource usage for small inputs can be classified as a security issue sometimes. But I also can't look that closely right now either. So this change is fine, just a little unfortunate we can't use someone else's code to validate.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
This is MUCH faster than asking libwebp to open the file!