CVE-2024-26685

/// Technical description

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

nilfs2: fix potential bug in end_buffer_async_write

According to a syzbot report, end_buffer_async_write(), which handles the

completion of block device writes, may detect abnormal condition of the

buffer async_write flag and cause a BUG_ON failure when using nilfs2.

Nilfs2 itself does not use end_buffer_async_write(). But, the async_write

flag is now used as a marker by commit 7f42ec394156 ("nilfs2: fix issue

with race condition of competition between segments for dirty blocks") as

a means of resolving double list insertion of dirty blocks in

nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the

resulting crash.

This modification is safe as long as it is used for file data and b-tree

node blocks where the page caches are independent. However, it was

irrelevant and redundant to also introduce async_write for segment summary

and super root blocks that share buffers with the backing device. Thi

/// 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