Fix integer underflow in Unit.resizeHeader() #25974
Closed
+1
−1
Conversation
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
When a DWARF unit has no previous unit (i.e., it's the first unit
in a section), the code incorrectly calculated `available_len = 0`,
even though there was actually `unit.off` bytes of available space
before the unit.
```zig
const available_len = if (unit.prev.unwrap()) |prev_unit| prev_excess: {
const prev_unit_ptr = sec.getUnit(prev_unit);
break :prev_excess unit.off - prev_unit_ptr.off - prev_unit_ptr.len;
} else 0; // ← BUG: Should be unit.off, not 0
```
Member
|
How is this change related to an integer underflow? |
It's an AI generated PR but this doesn't show the full reasoning why it's an integer underflow either. |
Member
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 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Outdated suggestions cannot be applied.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.
When a DWARF unit has no previous unit (i.e., it's the first unit in a section), the code incorrectly calculated
available_len = 0, even though there was actuallyunit.offbytes of available space before the unit.