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.
References
In
Chmoder::chmod()the recursive branch overwrites the running result instead of accumulating it, so the exit code reflects only the last file processed:PoC: GNU returns 1 when a file fails; uutils returns 0 if the last entry succeeds:
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.References