CVE-2024-26658

/// Technical description

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

bcachefs: grab s_umount only if snapshotting

When I was testing mongodb over bcachefs with compression,

there is a lockdep warning when snapshotting mongodb data volume.

$ cat test.sh

prog=bcachefs

$prog subvolume create /mnt/data

$prog subvolume create /mnt/data/snapshots

while true;do

$prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s)

sleep 1s

done

$ cat /etc/mongodb.conf

systemLog:

destination: file

logAppend: true

path: /mnt/data/mongod.log

storage:

dbPath: /mnt/data/

lockdep reports:

[ 3437.452330] ======================================================

[ 3437.452750] WARNING: possible circular locking dependency detected

[ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E

[ 3437.453562] ------------------------------------------------------

[ 3437.453981] bcachefs/35533 is trying to acquire lock:

[ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filen

/// 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