In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: do not ignore genmask when looking up chain by id
When adding a rule to a chain referring to its ID, if that chain had been deleted on the same batch, the rule might end up referring to a deleted chain.
This will lead to a WARNING like following:
[ 33.098431] ------------[ cut here ]------------ [ 33.098678] WARNING: CPU: 5 PID: 69 at net/netfilter/nf_tables_api.c:2037 nf_tables_chain_destroy+0x23d/0x260 [ 33.099217] Modules linked in: [ 33.099388] CPU: 5 PID: 69 Comm: kworker/5:1 Not tainted 6.4.0+ #409 [ 33.099726] Workqueue: events nf_tables_trans_destroy_work [ 33.100018] RIP: 0010:nf_tables_chain_destroy+0x23d/0x260 [ 33.100306] Code: 8b 7c 24 68 e8 64 9c ed fe 4c 89 e7 e8 5c 9c ed fe 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 c3 cc cc cc cc <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 [ 33.101271] RSP: 0018:ffffc900004ffc48 EFLAGS: 00010202 [ 33.101546] RAX: 0000000000000001 RBX: ffff888006fc0a28 RCX: 0000000000000000 [ 33.101920] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.102649] RBP: ffffc900004ffc78 R08: 0000000000000000 R09: 0000000000000000 [ 33.103018] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880135ef500 [ 33.103385] R13: 0000000000000000 R14: dead000000000122 R15: ffff888006fc0a10 [ 33.103762] FS: 0000000000000000(0000) GS:ffff888024c80000(0000) knlGS:0000000000000000 [ 33.104184] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.104493] CR2: 00007fe863b56a50 CR3: 00000000124b0001 CR4: 0000000000770ee0 [ 33.104872] PKRU: 55555554 [ 33.104999] Call Trace: [ 33.105113] <TASK> [ 33.105214] ? show_regs+0x72/0x90 [ 33.105371] ? __warn+0xa5/0x210 [ 33.105520] ? nf_tables_chain_destroy+0x23d/0x260 [ 33.105732] ? report_bug+0x1f2/0x200 [ 33.105902] ? handle_bug+0x46/0x90 [ 33.106546] ? exc_invalid_op+0x19/0x50 [ 33.106762] ? asm_exc_invalid_op+0x1b/0x20 [ 33.106995] ? nf_tables_chain_destroy+0x23d/0x260 [ 33.107249] ? nf_tables_chain_destroy+0x30/0x260 [ 33.107506] nf_tables_trans_destroy_work+0x669/0x680 [ 33.107782] ? mark_held_locks+0x28/0xa0 [ 33.107996] ? __pfx_nf_tables_trans_destroy_work+0x10/0x10 [ 33.108294] ? _raw_spin_unlock_irq+0x28/0x70 [ 33.108538] process_one_work+0x68c/0xb70 [ 33.108755] ? lock_acquire+0x17f/0x420 [ 33.108977] ? __pfx_process_one_work+0x10/0x10 [ 33.109218] ? do_raw_spin_lock+0x128/0x1d0 [ 33.109435] ? _raw_spin_lock_irq+0x71/0x80 [ 33.109634] worker_thread+0x2bd/0x700 [ 33.109817] ? __pfx_worker_thread+0x10/0x10 [ 33.110254] kthread+0x18b/0x1d0 [ 33.110410] ? __pfx_kthread+0x10/0x10 [ 33.110581] ret_from_fork+0x29/0x50 [ 33.110757] </TASK> [ 33.110866] irq event stamp: 1651 [ 33.111017] hardirqs last enabled at (1659): [<ffffffffa206a209>] __up_console_sem+0x79/0xa0 [ 33.111379] hardirqs last disabled at (1666): [<ffffffffa206a1ee>] __up_console_sem+0x5e/0xa0 [ 33.111740] softirqs last enabled at (1616): [<ffffffffa1f5d40e>] __irq_exit_rcu+0x9e/0xe0 [ 33.112094] softirqs last disabled at (1367): [<ffffffffa1f5d40e>] __irq_exit_rcu+0x9e/0xe0 [ 33.112453] ---[ end trace 0000000000000000 ]---
This is due to the nft_chain_lookup_byid ignoring the genmask. After this change, adding the new rule will fail as it will not find the chain.
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade python-perf-debuginfoUpgrade kernelUpgrade kernel-headersUpgrade bpftool-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-livepatch-5.10.184-175.749Upgrade python-perfUpgrade kernel-tools-debuginfoUpgrade perf-debuginfoUpgrade bpftoolUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-livepatch-5.15.120-74.144Upgrade kernel-debuginfoUpgrade kernel-toolsUpgrade kernel-develUpgrade kernel-tools-develUpgrade perf | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade bpftoolUpgrade kernelUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-tools-develUpgrade kernel-develUpgrade kernel-livepatch-6.1.38-59.109Upgrade python3-perfUpgrade kernel-toolsUpgrade python3-perf-debuginfoUpgrade kernel-libbpf-staticUpgrade kernel-libbpf-develUpgrade perf-debuginfoUpgrade kernel-headersUpgrade kernel-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-libbpfUpgrade perfUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-tools-debuginfo | Oct 16, 2025 | Oct 1, 2025 |
| Debian | — | Upgrade linux | Oct 3, 2025 | Oct 3, 2025 |
| Huawei Euleros 2_0_sp13 | — | Upgrade bpftoolUpgrade kernel-tools-libsUpgrade kernel-toolsUpgrade kernelUpgrade python3-perfUpgrade kernel-abi-stablelists | Mar 10, 2026 | Mar 10, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Oct 1, 2025 |
| Ubuntu | — | Upgrade linux-awsUpgrade linux-azureUpgrade linux-lowlatency-hwe-5.15Upgrade linux-ibmUpgrade linux-hwe-5.15Upgrade linuxUpgrade linux-realtimeUpgrade linux-gcp-5.15Upgrade linux-raspiUpgrade linux-azure-5.15Upgrade linux-intel-iotg-5.15Upgrade linux-lowlatencyUpgrade linux-intel-iotgUpgrade linux-intel-iot-realtimeUpgrade linux-gkeUpgrade linux-gkeopUpgrade linux-bluefieldUpgrade linux-riscv-5.15Upgrade linux-oracleUpgrade linux-xilinx-zynqmpUpgrade linux-nvidia-tegra-igxUpgrade linux-kvmUpgrade linux-gcpUpgrade linux-aws-5.15Upgrade linux-oracle-5.15Upgrade linux-nvidiaUpgrade linux-nvidia-tegraUpgrade linux-nvidia-tegra-5.15 | Oct 10, 2025 | Oct 1, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 15, 2025 | Oct 1, 2025 |
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