CVE-2024-50230: 
Linux Kernel vulnerability analysis and mitigation

CVE-2024-50230 affects the Linux kernel's nilfs2 filesystem component. The vulnerability was discovered by Syzbot and reported on October 17, 2024, involving a kernel bug that occurs during directory operations after nilfs2 detects filesystem corruption and degrades to read-only mode (Kernel Git). The issue affects multiple Linux kernel versions from 3.10 through 6.11.7 (NVD).

The vulnerability occurs when __block_write_begin_int() is called to prepare block writes and fails the BUG_ON check for accesses exceeding the folio/page size. This happens because the "checked" flag of a page/folio is not cleared when it is discarded by nilfs2's own routine, which causes the sanity check of directory entries to be skipped when the directory page/folio is reloaded. The issue has a CVSS v3.1 base score of 7.8 (High) with vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (NVD).

When exploited, this vulnerability can trigger a kernel bug in systems using the nilfs2 filesystem, particularly when the filesystem detects corruption and switches to read-only mode. The issue can lead to system instability and potential denial of service conditions (NVD).

A fix has been developed and committed to the Linux kernel, which involves adding code to clear the checked flag when the page/folio is discarded. The patch has been backported to multiple stable kernel versions. Users should update their Linux kernel to a patched version (Kernel Git).