CVE-2024-53057: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: net/sched: stop qdisc_tree_reduce_backlog on TC_H_ROOT In qdisc_tree_reduce_backlog, Qdiscs with major handle ffff: are assumed to be either root or ingress. This assumption is bogus since it's valid to create egress qdiscs with major handle ffff: Budimir Markovic found that for qdiscs like DRR that maintain an active class list, it will cause a UAF with a dangling class pointer. In 066a3b5b2346, the concern was to avoid iterating over the ingress qdisc since its parent is itself. The proper fix is to stop when parent TC_H_ROOT is reached because the only way to retrieve ingress is when a hierarchy which does not contain a ffff: major handle call into qdisc_lookup with TC_H_MAJ(TC_H_ROOT). In the scenario where major ffff: is an egress qdisc in any of the tree levels, the updates will also propagate to TC_H_ROOT, which then the iteration must stop. net/sched/sch_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

Affected products

• Linux Linux Kernel: from 2.6.25, before 4.19.323 (fixed in 4.19.323); from 4.20, before 5.4.285 (fixed in 5.4.285); from 5.5, before 5.10.229 (fixed in 5.10.229); from 5.11, before 5.15.171 (fixed in 5.15.171); from 5.16, before 6.1.116 (fixed in 6.1.116); from 6.2, before 6.6.60 (fixed in 6.6.60); …

Published 2024-11-19. Last modified 2026-06-17.