Avoid out of bounds access in String::fromCharCode #1254
Merged
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Outdated suggestions cannot be applied.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 c is negative (this can happen if char is signed), then accessing sConstStrings[c] is an out of bounds memory access. This results in a string being created from garbage memory, which can lead to seg faults later on.
Taking the other branch is safer in this case. While the behaviour with negative values is unspecified, it is unsafe to give out of bounds access to memory like this.
This is partly the cause of the crash in #865.