In the Linux kernel, the following vulnerability has been resolved:
netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm
When send a broadcast packet to a tap device, which was added to a bridge, br_nf_local_in() is called to confirm the conntrack. If another conntrack with the same hash value is added to the hash table, which can be triggered by a normal packet to a non-bridge device, the below warning may happen.
------------[ cut here ]------------ WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200 CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary) RIP: 0010:br_nf_local_in+0x168/0x200 Call Trace: <TASK> nf_hook_slow+0x3e/0xf0 br_pass_frame_up+0x103/0x180 br_handle_frame_finish+0x2de/0x5b0 br_nf_hook_thresh+0xc0/0x120 br_nf_pre_routing_finish+0x168/0x3a0 br_nf_pre_routing+0x237/0x5e0 br_handle_frame+0x1ec/0x3c0 __netif_receive_skb_core+0x225/0x1210 __netif_receive_skb_one_core+0x37/0xa0 netif_receive_skb+0x36/0x160 tun_get_user+0xa54/0x10c0 tun_chr_write_iter+0x65/0xb0 vfs_write+0x305/0x410 ksys_write+0x60/0xd0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> ---[ end trace 0000000000000000 ]---
To solve the hash conflict, nf_ct_resolve_clash() try to merge the conntracks, and update skb->_nfct. However, br_nf_local_in() still use the old ct from local variable 'nfct' after confirm(), which leads to this warning.
If confirm() does not insert the conntrack entry and return NF_DROP, the warning may also occur. There is no need to reserve the WARN_ON_ONCE, just remove it.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernelUpgrade bpftoolUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-livepatch-5.15.193-133.214Upgrade kernel-develUpgrade kernel-tools-develUpgrade kernel-toolsUpgrade perf-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-tools-debuginfoUpgrade python-perf-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-debuginfoUpgrade kernel-headersUpgrade python-perfUpgrade perf | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade perfUpgrade python3-perfUpgrade perf6.12-debuginfoUpgrade kernel-tools-debuginfoUpgrade kernel-livepatch-6.1.155-176.282Upgrade kernel6.12-debuginfoUpgrade kernel-develUpgrade kernel6.12Upgrade kernel-libbpfUpgrade kernel-tools-develUpgrade kernel6.12-debuginfo-common-x86_64Upgrade kernel-modules-extraUpgrade python3-perf-debuginfoUpgrade kernel6.12-headersUpgrade kernel-debuginfo-common-aarch64Upgrade kernel6.12-toolsUpgrade bpftool-debuginfoUpgrade python3-perf6.12Upgrade bpftoolUpgrade kernel-libbpf-staticUpgrade kernel-debuginfoUpgrade kernel6.12-develUpgrade kernel6.12-modules-extra-commonUpgrade kernel6.12-tools-develUpgrade kernel-libbpf-debuginfoUpgrade kernel-modules-extra-commonUpgrade bpftool6.12Upgrade kernel-livepatch-6.12.46-66.121Upgrade python3-perf6.12-debuginfoUpgrade kernel6.12-modules-extraUpgrade kernel-toolsUpgrade perf-debuginfoUpgrade kernel6.12-debuginfo-common-aarch64Upgrade bpftool6.12-debuginfoUpgrade kernelUpgrade kernel6.12-libbpf-staticUpgrade perf6.12Upgrade kernel6.12-tools-debuginfoUpgrade kernel-headersUpgrade kernel-debuginfo-common-x86_64Upgrade kernel6.12-libbpfUpgrade kernel6.12-libbpf-debuginfoUpgrade kernel-libbpf-develUpgrade kernel6.12-libbpf-devel | Oct 16, 2025 | Oct 1, 2025 |
| Debian | — | Upgrade linuxUpgrade linux-6.1 | Oct 2, 2025 | Oct 2, 2025 |
| Huawei Euleros 2_0_sp11 | — | Upgrade bpftoolUpgrade kernelUpgrade kernel-toolsUpgrade kernel-tools-libsUpgrade python3-perfUpgrade kernel-abi-stablelists | Mar 17, 2026 | Mar 17, 2026 |
| Huawei Euleros 2_0_sp12 | — | Upgrade bpftoolUpgrade kernel-tools-libsUpgrade kernelUpgrade kernel-toolsUpgrade python3-perfUpgrade kernel-abi-stablelists | Mar 17, 2026 | Mar 17, 2026 |
| Huawei Euleros 2_0_sp13 | — | Upgrade kernel-tools-libsUpgrade kernel-abi-stablelistsUpgrade kernel-toolsUpgrade bpftoolUpgrade kernelUpgrade python3-perf | Mar 10, 2026 | Mar 10, 2026 |
| Oracle_linux | — | Upgrade kernel-uek | Nov 11, 2025 | Oct 1, 2025 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Oct 1, 2025 |
| Ubuntu | — | Upgrade linux-image-ibmUpgrade linux-image-6.8.0-1050-aws-64kUpgrade linux-image-gcpUpgrade linux-image-ibm-classicUpgrade linux-image-nvidia-64k-hwe-22.04Upgrade linux-image-nvidia-lowlatency-6.8Upgrade linux-image-oem-20.04Upgrade linux-image-nvidia-6.8Upgrade linux-image-realtime-6.8.1Upgrade linux-image-lowlatency-hwe-20.04Upgrade linux-image-xilinx-6.8Upgrade linux-image-ibm-5.15Upgrade linux-image-5.15.0-1091-raspiUpgrade linux-image-6.8.0-2040-raspi-realtimeUpgrade linux-image-virtual-hwe-22.04Upgrade linux-image-oracle-5.15Upgrade linux-image-raspi-6.8Upgrade linux-image-azure-6.8Upgrade linux-image-nvidia-tegra-igx-rtUpgrade linux-image-raspiUpgrade linux-image-oem-22.04aUpgrade linux-image-gcp-64kUpgrade linux-image-6.8.0-106-genericUpgrade linux-image-nvidiaUpgrade linux-image-oracle-lts-24.04Upgrade linux-image-6.8.0-1035-gkeopUpgrade linux-image-5.15.0-1097-aws-fipsUpgrade linux-image-5.15.0-1092-intel-iotgUpgrade linux-image-realtime-hwe-22.04Upgrade linux-image-nvidia-tegra-igx-5.15Upgrade linux-image-6.8.0-1052-azure-fipsUpgrade linux-image-5.15.0-1092-nvidia-lowlatencyUpgrade linux-image-oem-22.04cUpgrade linux-image-virtual-hwe-20.04Upgrade linux-image-raspi-5.15Upgrade linux-image-intel-iot-realtimeUpgrade linux-image-nvidia-tegra-5.15Upgrade linux-image-nvidia-tegra-igx-rt-5.15Upgrade linux-image-intel-iotgUpgrade linux-image-kvm-5.15Upgrade linux-image-5.15.0-1080-gkeopUpgrade linux-image-6.8.0-1047-oracleUpgrade linux-image-6.8.0-106-fipsUpgrade linux-image-aws-6.8Upgrade linux-image-5.15.0-163-lowlatencyUpgrade linux-image-aws-fipsUpgrade linux-image-fipsUpgrade linux-image-6.8.0-1029-xilinxUpgrade linux-image-6.8.0-1050-awsUpgrade linux-image-azureUpgrade linux-image-raspi-realtime-6.8Upgrade linux-image-azure-lts-22.04Upgrade linux-image-6.8.0-106-generic-64kUpgrade linux-image-gke-6.8Upgrade linux-image-xilinx-zynqmpUpgrade linux-image-intelUpgrade linux-image-gke-64k-6.8Upgrade linux-image-nvidia-tegra-rt-5.15Upgrade linux-image-generic-lpae-5.15Upgrade linux-image-nvidia-64kUpgrade linux-image-gke-5.15Upgrade linux-image-5.15.0-1097-awsUpgrade linux-image-5.15.0-1096-realtimeUpgrade linux-image-6.8.0-1051-azureUpgrade linux-image-oracle-64k-6.8Upgrade linux-image-5.15.0-163-genericUpgrade linux-image-intel-iotg-5.15Upgrade linux-image-raspi-realtimeUpgrade linux-image-5.15.0-163-generic-lpaeUpgrade linux-image-6.8.0-1049-nvidia-lowlatencyUpgrade linux-image-lowlatency-64kUpgrade linux-image-lowlatency-5.15Upgrade linux-image-realtime-5.15Upgrade linux-image-nvidia-tegraUpgrade linux-image-6.8.0-1052-gcp-64kUpgrade linux-image-genericUpgrade linux-image-generic-lpaeUpgrade linux-image-gcp-fipsUpgrade linux-image-gkeUpgrade linux-image-gcp-64k-lts-24.04Upgrade linux-image-aws-64k-lts-22.04Upgrade linux-image-virtual-6.8Upgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-generic-64kUpgrade linux-image-lowlatencyUpgrade linux-image-aws-64kUpgrade linux-image-azure-fips-5.15Upgrade linux-image-6.8.0-1049-ibmUpgrade linux-image-gcp-fips-6.8Upgrade linux-image-5.15.0-1097-gcpUpgrade linux-image-5.15.0-163-fipsUpgrade linux-image-6.8.0-1048-gke-64kUpgrade linux-image-5.15.0-1102-azureUpgrade linux-image-oem-20.04bUpgrade linux-image-oem-22.04Upgrade linux-image-gkeop-6.8Upgrade linux-image-oracle-64kUpgrade linux-image-generic-64k-hwe-20.04Upgrade linux-image-gkeopUpgrade linux-image-xilinxUpgrade linux-image-fips-5.15Upgrade linux-image-5.15.0-1093-gkeUpgrade linux-image-6.8.0-1049-nvidiaUpgrade linux-image-6.8.0-106-lowlatency-64kUpgrade linux-image-6.8.1-1045-realtimeUpgrade linux-image-6.8.0-1048-gkeUpgrade linux-image-5.15.0-1049-nvidia-tegra-rtUpgrade linux-image-azure-lts-24.04Upgrade linux-image-nvidia-5.15Upgrade linux-image-oem-20.04cUpgrade linux-image-5.15.0-163-lowlatency-64kUpgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1049-nvidia-lowlatency-64kUpgrade linux-image-5.15.0-1061-xilinx-zynqmpUpgrade linux-image-oracle-64k-lts-24.04Upgrade linux-image-generic-5.15Upgrade linux-image-gcp-lts-22.04Upgrade linux-image-gcp-64k-6.8Upgrade linux-image-azure-fipsUpgrade linux-image-aws-64k-5.15Upgrade linux-image-intel-iot-realtime-5.15Upgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-5.15.0-1091-ibmUpgrade linux-image-generic-64k-5.15Upgrade linux-image-awsUpgrade linux-image-oem-22.04dUpgrade linux-image-nvidia-lowlatencyUpgrade linux-image-lowlatency-6.8Upgrade linux-image-generic-64k-6.8Upgrade linux-image-azure-cvmUpgrade linux-image-azure-5.15Upgrade linux-image-6.8.0-1052-gcp-fipsUpgrade linux-image-6.8.0-1052-gcpUpgrade linux-image-xilinx-zynqmp-5.15Upgrade linux-image-oem-20.04dUpgrade linux-image-oracleUpgrade linux-image-gcp-lts-24.04Upgrade linux-image-gcp-fips-5.15Upgrade linux-image-5.15.0-163-generic-64kUpgrade linux-image-oracle-lts-22.04Upgrade linux-image-ibm-6.8Upgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-raspi-nolpaeUpgrade linux-image-nvidia-hwe-22.04Upgrade linux-image-realtimeUpgrade linux-image-6.8.0-1047-oracle-64kUpgrade linux-image-5.15.0-1049-nvidia-tegraUpgrade linux-image-6.8.0-1050-aws-fipsUpgrade linux-image-aws-lts-22.04Upgrade linux-image-fips-6.8Upgrade linux-image-generic-lpae-hwe-20.04Upgrade linux-image-gcp-5.15Upgrade linux-image-oem-22.04bUpgrade linux-image-generic-hwe-22.04Upgrade linux-image-lowlatency-64k-5.15Upgrade linux-image-ibm-lts-24.04Upgrade linux-image-gcp-6.8Upgrade linux-image-azure-fips-6.8Upgrade linux-image-aws-fips-6.8Upgrade linux-image-aws-64k-6.8Upgrade linux-image-6.8.0-106-lowlatencyUpgrade linux-image-6.8.0-1050-raspiUpgrade linux-image-5.15.0-1101-azure-fipsUpgrade linux-image-5.15.0-1097-gcp-fipsUpgrade linux-image-aws-fips-5.15Upgrade linux-image-nvidia-tegra-rtUpgrade linux-image-nvidia-lowlatency-5.15Upgrade linux-image-generic-hwe-20.04Upgrade linux-image-5.15.0-1101-azureUpgrade linux-image-5.15.0-1097-aws-64kUpgrade linux-image-5.15.0-1089-intel-iot-realtimeUpgrade linux-image-aws-lts-24.04Upgrade linux-image-aws-64k-lts-24.04Upgrade linux-image-aws-5.15Upgrade linux-image-5.15.0-1094-oracleUpgrade linux-image-virtualUpgrade linux-image-oracle-6.8Upgrade linux-image-nvidia-tegra-igxUpgrade linux-image-lowlatency-64k-hwe-20.04Upgrade linux-image-nvidia-lowlatency-64k-6.8Upgrade linux-image-gkeop-5.15Upgrade linux-image-kvmUpgrade linux-image-5.15.0-1092-nvidiaUpgrade linux-image-virtual-5.15Upgrade linux-image-5.15.0-1089-kvmUpgrade linux-image-5.15.0-1038-nvidia-tegra-igx-rtUpgrade linux-image-5.15.0-1038-nvidia-tegra-igxUpgrade linux-image-gke-64kUpgrade linux-image-generic-6.8Upgrade linux-image-6.8.0-1049-nvidia-64kUpgrade linux-image-lowlatency-64k-6.8Upgrade linux-image-nvidia-64k-6.8 | Dec 5, 2025 | Oct 1, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 17, 2025 | Oct 1, 2025 |
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