[programs] guard mallocAndJoin2Dir against size_t overflow#4661
Open
Wingingbump wants to merge 1 commit into
Open
[programs] guard mallocAndJoin2Dir against size_t overflow#4661Wingingbump wants to merge 1 commit into
Wingingbump wants to merge 1 commit into
Conversation
When `dir1Size + dir2Size + 2` exceeds SIZE_MAX, the sum wraps to a small value, causing malloc() to allocate an undersized buffer and the subsequent memcpy() calls to overflow the heap. Add a CONTROL() check so the overflow is caught before the allocation. Reported in facebook#4642.
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
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Summary
mallocAndJoin2Dirsodir1Size + dir2Size + 2cannot wrapsize_tand produce an undersized malloc that the followingmemcpy()s would overrun.CONTROL()pattern, matching how the function already handles allocation failure.Fixes #4642.
Test plan