Potential fix for code scanning alert no. 2391: Arbitrary file write extracting an archive containing symbolic links - #6252
Draft
eriknordmark wants to merge 1 commit into
Draft
Potential fix for code scanning alert no. 2391: Arbitrary file write extracting an archive containing symbolic links#6252eriknordmark wants to merge 1 commit into
eriknordmark wants to merge 1 commit into
Conversation
…extracting an archive containing symbolic links Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
![github-advanced-security[bot]](https://avatars.githubusercontent.com/in/57789?s=60&v=4){kind=small}
| return fmt.Errorf("ExtractFromTar: MkdirAll(destination) failed: %w", err) | ||
| } | ||
| realDestination, err := filepath.EvalSymlinks(cleanDestination) | ||
| if err != nil { |
Contributor
|
What about using https://pkg.go.dev/os#OpenRoot then you don't need these validation lambdas, do you? |
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
3 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Potential fix for https://github.com/lf-edge/eve/security/code-scanning/2391
To fix this safely, validate every extracted output path (and symlink target path) against the destination directory using canonical, symlink-aware resolution before creating files/dirs/symlinks. Also avoid using
pathfor OS filesystem paths; usepath/filepath.Best fix here (without changing intended behavior): in
evetest/utils/tar.go, replace the simplepathBuilderwith a secure resolver that:filepath.Join.filepath.EvalSymlinks(or destination for root parent).filepath.Reland..check.Then use this resolver in all three branches (
TypeDir,TypeReg,TypeLink/TypeSymlink) and create symlink with validated link target and validated link path.Suggested fixes powered by Copilot Autofix. Review carefully before merging.