GHSA-4x34-chg5-mwjj chmod: recursive mode returns exit code 0 even when some files fail (last-file-wins)

• crates.io uu_chmod: < 0.6.0 → fixed in 0.6.0

In `Chmoder::chmod()` the recursive branch overwrites the running result instead of accumulating it, so the exit code reflects only the *last* file processed: ``` if self.recursive { r = self.walk_dir_with_context(file, true); // overwrites r } else { r = self.chmod_file(file).and(r); } ``` PoC: GNU returns 1 when a file fails; uutils returns 0 if the last entry succeeds: ``` $ chmod -R 0755 chmod-bug/root chmod-bug/user # GNU -> ret=1 $ uutils chmod -R 0755 chmod-bug/root chmod-bug/user # -> ret=0 ``` Impact: scripts relying on the exit code get a false success signal while some files retained restrictive/unexpected permissions, leading to access-control misconfigurations. Recommendation: accumulate errors during traversal. Remediation: Acknowledged by Canonical; fixed in commit abd581f6. --- _Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.2. Credit: Zellic._