A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8fc134fee27f2263988ae38920bc03da416b03d8 | patch mailing list exploit vendor advisory |
| https://kernel.dance/8fc134fee27f2263988ae38920bc03da416b03d8 | patch vendor advisory exploit |
| https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html | third party advisory mailing list |
| https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html | third party advisory mailing list |