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 blocks As Paolo said earlier [1]: "Since the blamed commit below, classify can return TC_ACT_CONSUMED while the current skb being held by the defragmentation engine. As reported by GangMin Kim, if such packet is that may cause a UaF when the defrag engine later on tries to tuch again such packet." act_ct was never meant to be used in the egress path, however some users are attaching it to egress today [2]. Attempting to reach a middle ground, we noticed that, while most qdiscs are not handling TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we address the issue by only allowing act_ct to bind to clsact/ingress qdiscs and shared blocks. That way it's still possible to attach act_ct to egress (albeit only with clsact). [1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/ [2] https://lore.kernel.org/netdev/[email protected]/
How to fix
- linux linux_kernel5.15.203, 6.1.167, 6.6.130, 6.8, 6.12.77, 6.18.18, 6.19.8 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 5.15.148 ≤ v < 5.15.203, 6.1.75 ≤ v < 6.1.167, 6.6.14 ≤ v < 6.6.130, 6.7.2 ≤ v < 6.8, 6.8 ≤ v < 6.12.77, 6.13 ≤ v < 6.18.18, 6.19 ≤ v < 6.19.8, 7.0 | 5.15.203, 6.1.167, 6.6.130, 6.8, 6.12.77, 6.18.18, 6.19.8 |
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