PT-2026-27757 · Linux · Linux

Published 2026-03-25 · Updated 2026-03-25 · CVE-2026-23392

NVD

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf tables: release flowtable after rcu grace period on error

Call synchronize rcu() after unregistering the hooks from error path, since a hook that already refers to this flowtable can be already registered, exposing this flowtable to packet path and nfnetlink hook control plane.

This error path is rare, it should only happen by reaching the maximum number hooks or by failing to set up to hardware offload, just call synchronize rcu().

There is a check for already used device hooks by different flowtable that could result in EEXIST at this late stage. The hook parser can be updated to perform this check earlier to this error path really becomes rarely exercised.

Uncovered by KASAN reported as use-after-free from nfnetlink hook path when dumping hooks.

Related Identifiers

CVE-2026-23392

Affected Products

Linux

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-23392 · Security Note
• https://git.kernel.org/stable/c/d2632de96ccb066e0131ad1494241b9c281c60b8 · Note
• https://git.kernel.org/stable/c/7e3955b282eae20d61c75e499c75eade51c20060 · Note
• https://git.kernel.org/stable/c/c8092edb9a11f20f95ccceeb9422b7dd0df337bd · Note
• https://twitter.com/CVEnew/status/2036763449116483601 · Twitter Post
• https://git.kernel.org/stable/c/d73f4b53aaaea4c95f245e491aa5eeb8a21874ce · Note
• https://git.kernel.org/stable/c/adee3436ccd29f1e514c028899e400cbc6d84065 · Note
• https://git.kernel.org/stable/c/e78a2dcc7cfb87b64a631441ca7681492b347ef6 · Note