CVE-2024-49854: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

Affected products

• Linux Linux Kernel: from 5.10.227, before 5.15.168 (fixed in 5.15.168); from 5.16, before 6.1.113 (fixed in 6.1.113); from 6.2, before 6.6.54 (fixed in 6.6.54); from 6.7, before 6.10.13 (fixed in 6.10.13); from 6.11, before 6.11.2 (fixed in 6.11.2)

Published 2024-10-21. Last modified 2026-08-04.