Executive brief
A vulnerability in the Linux kernel's UBIFS file system could allow a local user to crash the system. UBIFS is a file system designed for unmanaged flash memory devices. By triggering a specific sequence of memory management actions followed by a file system debug operation, an attacker can cause a system-wide denial of service.
Technical details
A NULL pointer dereference exists in fs/ubifs/debug.c within the ubifs_dump_tnc function. The vulnerability is triggered when the slab cache is cleared, which frees all znodes in memory and sets the root znode (c->zroot.znode) to NULL. Subsequent calls to ubifs_dump_tnc attempt to access this NULL pointer without validation, leading to a kernel panic. This is a local attack vector requiring low privileges to trigger the crash. Patches have been released across multiple stable kernel branches to add a check for the NULL zroot before proceeding with the TNC dump.
Affected products
- Linux Linux Kernel 2.6.27 to 5.4.291, 5.5 to 5.10.235, 5.11 to 5.15.179, 5.16 to 6.1.129, 6.2 to 6.6.76, 6.7 to 6.12.13, 6.13 to 6.13.2
Timeline
- 2024-12-24: other: Initial patch authored
- 2025-03-06: advisory: NVD publication date
- 2025-03-13: patched: Final stable branch patches committed
References
- https://git.kernel.org/stable/c/1787cd67bb94b106555ffe64f887f6aa24b47010
- https://git.kernel.org/stable/c/2a987950df825d0144370e700dc5fb337684ffba
- https://git.kernel.org/stable/c/40e25a3c0063935763717877bb2a814c081509ff
- https://git.kernel.org/stable/c/428aff8f7cfb0d9a8854477648022cef96bcab28
- https://git.kernel.org/stable/c/6211c11fc20424bbc6d79c835c7c212b553ae898
- https://git.kernel.org/stable/c/77e5266e3d3faa6bdcf20d9c68a8972f6aa06522
- https://git.kernel.org/stable/c/bdb0ca39e0acccf6771db49c3f94ed787d05f2d7