Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.15.151 – < 5.15.192, 6.1.81 – < 6.1.151, 6.6.21 – < 6.6.105, 6.7.9 – < 6.8, 6.8 | 5.15.192 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.16.6-1 | — |
| Debian 13 | linux | 6.12.48-1 | — |
| Debian 12 | linux | 6.1.153-1 | — |
| Debian 11 | linux-6.1 | 6.1.153-1~deb11u1 | DLA-4328-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1017.21 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1081.83 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-106.106 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1050.53 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1051.57 | USN-8125-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1058.65 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1052.55 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1048.53 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1035.38 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1049.49 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-intel +19 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-106.106.1 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1049.52 | USN-8100-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1049.52.1 | USN-8100-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1047.48 | USN-8095-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1050.54 | USN-8095-5 |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1028.29 | USN-8261-1 |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-163.173 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1097.104 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1050.53~22.04.1 | USN-8095-4 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1101.110 | USN-7910-2 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1102.111.1 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1097.106 | USN-7909-4 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1052.55~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1093.99 | USN-7909-4 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1080.88 | USN-7909-4 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-106.106~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1091.94 | USN-7909-5, USN-7909-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1049.49~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1092.98 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1089.94 | USN-7933-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-106.106.1~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1092.93 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1049.52~22.04.1 | USN-8100-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1049.49 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1038.38 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1094.100 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1047.48~22.04.1 | USN-8095-1 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1061.65 | USN-7909-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2040.41 | USN-8095-5 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1045.46 | USN-8095-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1089.91 | USN-7909-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1096.105 | USN-7909-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1045.46~22.04.1 | USN-8095-3 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1050.53+fips1 | USN-8095-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1052.58+fips1 | USN-8165-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-106.106+fips1 | USN-8095-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1052.55+fips1 | USN-8095-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1097.104+fips1 | USN-7909-3 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1101.110+fips1 | USN-7910-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-163.173+fips1 | USN-7909-3 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1097.106+fips1 | USN-7909-3 |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1097.104~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1102.111~20.04.1 | USN-7938-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1097.106~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-163.173~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 | 5.15.0-1091.94~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1092.98~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1049.49~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1094.100~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-riscv-5.15 | 5.15.0-1092.96~20.04.1 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.36.1 | SUSE-SU-2026:22835-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.36.1.160000.2.17 | SUSE-SU-2026:22835-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.36.1 | SUSE-SU-2026:22835-1, SUSE-SU-2026:22812-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.36.1.160000.2.17 | SUSE-SU-2026:22835-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.36.1.160000.2.17 | SUSE-SU-2026:22769-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.36.1 | SUSE-SU-2026:22769-1, SUSE-SU-2026:22742-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.36.1.160000.2.17 | openSUSE-SU-2026:21388-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.36.1 | openSUSE-SU-2026:21388-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.46-66.121 +1 | 1:1.0-0.amzn2023 | ALAS2023-2025-1223, ALAS2023-2025-1208 |
| Amazon Linux 2023 | perf +14 | 1:6.1.155-176.282.amzn2023 | ALAS2023-2025-1223 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.46-66.121.amzn2023 | ALAS2023-2025-1208 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | kernel | 5.15.200.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-105.51.5.el10uek | ELSA-2025-25754 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-314.193.5.3.el9uek | ELSA-2025-25757 |
Advisories 30
- WID-SEC-2025-2170 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8100-1 linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8165-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8095-1 linux, linux-aws, linux-gcp, linux-gcp-6.8, linux-gke, linux-gkeop, linux-hwe-6.8, linux-ibm, linux-ibm-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-1 linux, linux-aws, linux-aws-5.15, linux-gcp-5.15, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx, linux-oracle, linux-oracle-5.15, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-2 linux-fips, linux-aws-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-5 linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8125-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-4 linux-aws-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8095-3 linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-3 linux-aws-fips, linux-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-4 linux-gcp, linux-gke, linux-gkeop vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7938-1 linux-azure-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7933-1 linux-kvm vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-5 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7910-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-2 linux-intel-iot-realtime, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7910-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8261-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- SUSE-SU-2026:22835-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 28, 2026
- SUSE-SU-2026:22812-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 28, 2026
- openSUSE-SU-2026:21388-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 24, 2026
- SUSE-SU-2026:22769-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 23, 2026
- SUSE-SU-2026:22742-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 23, 2026
- DLA-4328-1 linux-6.1 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- ELSA-2025-25757 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2025
- ELSA-2025-25754 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 9, 2025
- ALAS2023-2025-1208 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 18, 2025
- ALAS2023-2025-1223 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 14, 2025
References
- https://git.kernel.org/stable/c/d00c8b0daf56012f69075e3377da67878c775e4c
- https://git.kernel.org/stable/c/ccbad4803225eafe0175d3cb19f0d8d73b504a94
- https://git.kernel.org/stable/c/50db11e2bbb635e38e3dd096215580d6adb41fb0
- https://git.kernel.org/stable/c/c47ca77fee9071aa543bae592dd2a384f895c8b6
- https://git.kernel.org/stable/c/a74abcf0f09f59daeecf7a3ba9c1d690808b0afe
- https://git.kernel.org/stable/c/479a54ab92087318514c82428a87af2d7af1a576