CVE-2023-54140

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse

A syzbot stress test using a corrupted disk image reported that

mark_buffer_dirty() called from __nilfs_mark_inode_dirty() or

nilfs_palloc_commit_alloc_entry() may output a kernel warning, and can

panic if the kernel is booted with panic_on_warn.

This is because nilfs2 keeps buffer pointers in local structures for some

metadata and reuses them, but such buffers may be forcibly discarded by

nilfs_clear_dirty_page() in some critical situations.

This issue is reported to appear after commit 28a65b49eb53 ("nilfs2: do

not write dirty data after degenerating to read-only"), but the issue has

potentially existed before.

Fix this issue by checking the uptodate flag when attempting to reuse an

internally held buffer, and reloading the metadata instead of reusing the

buffer if the flag was lost.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References