CVE-2026-23270

Description

In the Linux kernel, the following vulnerability has been resolved:net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocksAs Paolo said earlier [1]:Since the blamed commit below, classify can return TC_ACT_CONSUMED whilethe current skb being held by the defragmentation engine. As reported byGangMin Kim, if such packet is that may cause a UaF when the defrag enginelater on tries to tuch again such packet.act_ct was never meant to be used in the egress path, however some usersare attaching it to egress today [2]. Attempting to reach a middleground, we noticed that, while most qdiscs are not handlingTC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, weaddress the issue by only allowing act_ct to bind to clsact/ingressqdiscs and shared blocks. That way its still possible to attach act_ct toegress (albeit only with clsact).[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/

Risk Information

Base Score

7.8

MODERATE

Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score

Exploitation Probability

0.013

Associated Vulnerability

No records found

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234