CVE-2024-53218: 
Linux Debian vulnerability analysis and mitigation

In the Linux kernel, a race condition vulnerability (CVE-2024-53218) was discovered in the f2fs filesystem's gcthread handling. The vulnerability was reported on December 27, 2024, affecting the concurrent f2fsstopgcthread functionality. This issue occurs during filesystem shutdown operations when multiple threads attempt to stop the garbage collection thread simultaneously (NVD).

The vulnerability manifests as a race condition in f2fsstopgcthread() when called from different f2fs shutdown paths. The issue occurs when two CPUs concurrently execute the stopgcthread function, leading to a use-after-free condition. One thread frees the gcthread structure while another thread attempts to access it, resulting in a general protection fault. The vulnerability has been assigned a CVSS v3.1 base score of 7.8 (HIGH) with vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (CISA-ADP).

When successfully exploited, this vulnerability can lead to a system crash (denial of service) through a general protection fault. The issue potentially allows for use-after-free exploitation, which could result in privilege escalation or arbitrary code execution in the kernel context (NVD).

The vulnerability has been fixed by converting to write lock of sumount in f2fsdo_shutdown(). The previous attempt to fix this issue using a read semaphore (commit c7f114d864ac) was insufficient to prevent all race conditions. Users should update to the patched version of the Linux kernel that includes this fix (Kernel Git).