Executive brief
A vulnerability was identified in the Linux kernel's s390 architecture subsystem. It involves a technical error in how the system handles hardware drivers, which could potentially lead to a system crash or unpredictable behavior. This issue has been resolved in recent kernel updates by implementing a more secure way to manage driver assignments.
Technical details
A use-after-free (UAF) vulnerability exists in the s390/cio subsystem of the Linux kernel. The issue stems from the `match()` callback in the `__driver_attach()` function being called without holding the necessary device lock. This allows the `driver_override` field to be accessed concurrently without synchronization, leading to a race condition and potential UAF. The fix involves migrating the s390/cio driver to the generic `driver_override` infrastructure provided by the kernel core, which handles the required locking internally. This vulnerability affects Linux kernel versions from 5.3 up to 7.1.
Affected products
- Linux Linux 5.3 to 7.1
Timeline
- 2026-06-24: advisory: CVE-2026-53117 published by NVD
- 2026-06-24: patched: Fixes merged into various stable kernel branches
References
- https://git.kernel.org/stable/c/106d594711e97762788046c5bbb94f580abc4bf4
- https://git.kernel.org/stable/c/2081957d8c323ffb58a10bc64837717ac5a042a1
- https://git.kernel.org/stable/c/ac4d8bb6e2e13e8684a76ea48d13ebaaaf5c24c4
- https://git.kernel.org/stable/c/b660ba045b2b22cf3b4be72773de00cb48f47be5
- https://git.kernel.org/stable/c/c4295487124f461405e1ef64dfa8c4ab0cb7ebcf