Executive brief
A vulnerability was identified in the Linux kernel's F2FS file system component. Under specific conditions, a local user could cause the system to read inconsistent data or crash by simultaneously viewing and modifying file extension lists through the system interface. This primarily impacts system stability and could lead to a denial-of-service.
Technical details
A race condition exists in the f2fs_sbi_show() function within the F2FS file system implementation of the Linux kernel. The extension_list, extension_count, and hot_ext_count variables are accessed without proper synchronization (sb_lock). If a concurrent process modifies these values via f2fs_update_extension_list() through a sysfs store operation, the show path may read inconsistent array bounds and contents. This can result in out-of-bounds memory access or the disclosure of stale kernel data. The vulnerability is reachable via the sysfs interface and has been patched by ensuring the sb_lock is held during the entire read and format operation.
Affected products
- Linux Linux 4.17 to 7.0.10
Timeline
- 2026-04-10: other: Vulnerability fixed in source code by Yongpeng Yang
- 2026-06-26: advisory: CVE-2026-53303 published
References
- https://git.kernel.org/stable/c/4b3a1bf4c2ffd4c9595d900ead78c9035894a025
- https://git.kernel.org/stable/c/5909bedbed38c558bee7cb6758ceedf9bc3a9194
- https://git.kernel.org/stable/c/cea15f66b7b68b2c50943a6660e0692c6635e4eb
- https://git.kernel.org/stable/c/d0e877810baf613b018fd9747440b9d4d9db1428
- https://git.kernel.org/stable/c/d3ff0c121bbaef026df6248ab7ef6f0b068b0647
- https://git.kernel.org/stable/c/ea3ab43a1f3cf2c7cecd75c8be1ee99a5e94a92e