mknod: Device nodes created mislabeled on SELinux, with broken cleanup (remove_dir on a node)

uutils calls mknod before setting the SELinux context (GNU uses setfscreatecon first, labeling atomically). If set_selinux_security_context fails, cleanup uses std::fs::remove_dir, which cannot remove device nodes or FIFOs, leaving the mislabeled node behind.

Impact: on SELinux-enforcing systems the node is created with the wrong context; the command reports failure but leaves a mislabeled device node that may bypass mandatory access control, and orphaned nodes can persist across reboots. Recommendation: use setfscreatecon before mknod, abort on failure, and use remove_file for cleanup.

Remediation: Acknowledged by Canonical.

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Reported by Zellic in the uutils coreutils Program Security Assessment (prepared for Canonical, Jan 20 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242. Finding 3.58. Credit: Zellic.