Linux vulnerability

What happened

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

Affected versions

Linux: 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before 0521e694d5b80899fba8695881a6349f9bc538cb (git); 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before 4681960bc0f4f8bcc782cbf2fd205f48ad314dfd (git); 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before 4ce2a0c3b8497a66cfc25fc7ca3d087258a785d2 (git); 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before 3f358a66a04513311668ea4b40f5064e253d8386 (git); 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before cf23d531a9d496863aa4c5a0e2f71f0a23f3df3c (git); 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before d7615bde541f16517d6790412da6ec46fa8a4c1f (git); 78d9f48f7f44431a25da2b46b3a8812f6ff2b981 through before cf5fb87fcdaaaafec55dcc0dc5a9e15ead343973 (git); 5.8 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.