CVE-2024-53057 net/sched: stop qdisc_tree_reduce_backlog on TC_H_ROOT
A use-after-free vulnerability in the Linux kernel's network scheduler allows local attackers to execute arbitrary code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-53057?
CVE-2024-53057 is a high-severity use after free vulnerability in Linux kernel, published on 19 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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(-)
Weakness: CWE-416
Which versions are affected by CVE-2024-53057?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-53057?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2024-53057 being exploited?
There is no known exploitation of CVE-2024-53057 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-53855, AZL-53921, BELL-CVE-2024-53057, DEBIAN-CVE-2024-53057, GHSA-j5vh-vfg7-3v94, UBUNTU-CVE-2024-53057 and 1 more.