netfilter: nf_tables: reject duplicate device on updates

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: reject duplicate device on updates A chain/flowtable update with duplicated devices in the same batch is possible. Unfortunately, netdev event path only removes the first device that is found, leaving unregistered the hook of the duplicated device. Check if a duplicated device exists in the transaction batch, bail out with EEXIST in such case. WARNING is hit when unregistering the hook: [49042.221275] WARNING: CPU: 4 PID: 8425 at net/netfilter/core.c:340 nf_hook_entry_head+0xaa/0x150 [49042.221375] CPU: 4 UID: 0 PID: 8425 Comm: nft Tainted: G S 6.16.0+ #170 PREEMPT(full) [...] [49042.221382] RIP: 0010:nf_hook_entry_head+0xaa/0x150

Timeline

1. Sep 3, 2025, 1:01 PM UTCCVE published
2. Oct 15, 2026, 9:52 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 15, 2026, 10:02 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in 0521e694d5b80899fba8695881a6349f9bc538cb; From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in 4681960bc0f4f8bcc782cbf2fd205f48ad314dfd; From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in 4ce2a0c3b8497a66cfc25fc7ca3d087258a785d2; From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in 3f358a66a04513311668ea4b40f5064e253d8386; From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in cf23d531a9d496863aa4c5a0e2f71f0a23f3df3c; From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in d7615bde541f16517d6790412da6ec46fa8a4c1f; From 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 · fixed in cf5fb87fcdaaaafec55dcc0dc5a9e15ead343973

• Linux Linux

  5.8

• KernelLinux

  From 5.8.0 · fixed in 5.10.247; From 5.11.0 · fixed in 5.15.197; From 5.16.0 · fixed in 6.1.159; From 6.2.0 · fixed in 6.6.117; From 6.7.0 · fixed in 6.12.59; From 6.13.0 · fixed in 6.16.2

References 7