CVE-2024-26696

/// Technical description

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

nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()

Syzbot reported a hang issue in migrate_pages_batch() called by mbind()

and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2.

While migrate_pages_batch() locks a folio and waits for the writeback to

complete, the log writer thread that should bring the writeback to

completion picks up the folio being written back in

nilfs_lookup_dirty_data_buffers() that it calls for subsequent log

creation and was trying to lock the folio. Thus causing a deadlock.

In the first place, it is unexpected that folios/pages in the middle of

writeback will be updated and become dirty. Nilfs2 adds a checksum to

verify the validity of the log being written and uses it for recovery at

mount, so data changes during writeback are suppressed. Since this is

broken, an unclean shutdown could potentially cause recovery to fail.

Investigation revealed that the root cause

/// 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