Description
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: tp_meter: avoid divide-by-zero for dec_cwnd
The cwnd is always MSS <= cwnd <= 0x20000000. But the calculation in
batadv_tp_update_cwnd() assumes unsigned 32 bit arithmetics.
((mss * 8) ** 2) / (cwnd * 8)
In case cwnd is actually 0x20000000, it will be shifted by 3 bit to the
left end up at 0x100000000 or U32_MAX + 1. It will therefore wrap around
and be 0 - resulting in:
((mss * 8) ** 2) / 0
This is of course invalid and cannot be calculated. The calculation should
must be simplified to avoid this overflow:
(mss ** 2) * 8 / cwnd
It will keep the precision enhancement from the scaling (by 8) but avoid
the overflow in the divisor.
In theory, there could still be an overflow in the dividend. It is at the
moment fixed to BATADV_TP_PLEN in batadv_tp_recv_ack() - so it is not an
imminent problem. But allowing it to use the whole u32 bit range, would
mean that it can still use up to 67 bits. To keep this calculation safe for
32 bit arithmetic, mss must never use more than floor((32 - 3) / 2) bits -
or in other words: must never be larger than 16383.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.8 | 5.10.260 |
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 | 7.1.3-1 | — |
| Debian 13 | linux | 6.12.95-1 | — |
| Debian 12 | linux | 6.1.177-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1033.38 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1101.103 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-31.31 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-aws | 7.0.0-1012.12 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1014.14 | USN-8726-4 |
| Ubuntu 26.04 LTS | linux-gcp +1 | 7.0.0-1011.11 | USN-8726-4, USN-8726-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1006.7 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-ibm +2 | 7.0.0-1013.13 | USN-8727-1, USN-8726-3 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1018.18 | USN-8760-2 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2018.18 | USN-8800-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1019.19 | USN-8726-2 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-31.31.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux | 6.8.0-147.147 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1067.70 | USN-9024-1, USN-8917-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 | 7.0.0-1012.12~24.04.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1014.14~24.04.1 | USN-8728-2 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1069.76 | USN-8918-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1013.13~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gcp +1 | 6.8.0-1071.79 | USN-8918-1, USN-8917-1 |
| Ubuntu 24.04 LTS | linux-gcp-7.0 +1 | 7.0.0-1011.11~24.04.1 | USN-8728-3, USN-8728-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1066.74 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1052.56 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-31.31~24.04.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1067.68 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-147.147.1 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1018.18~24.04.1 | USN-8760-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1067.70.1 | USN-9040-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1039.40 | USN-9091-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1064.67 | USN-8917-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1068.72 | USN-9025-1 |
| Ubuntu 24.04 LTS | linux-riscv +29 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-31.31.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1008.8 | — |
| Ubuntu 22.04 LTS | linux | 5.15.0-198.208 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1117.124 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1069.74~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1123.132 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1073.82~22.04.1 | USN-9026-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1122.131 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1071.78~22.04.1 | USN-9026-1 |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1118.128 | USN-8877-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1073.81~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1113.119 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1100.108 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-149.149~22.04.1 | USN-9066-1 |
| Ubuntu 22.04 LTS | linux-ibm | 5.15.0-1111.115 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1069.70~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1112.118 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1109.114 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-195.205 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-149.149.1~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1112.113 | USN-8875-2 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1070.72 | USN-8963-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1059.59 | USN-8963-1 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1114.120 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1067.71~22.04.1 | USN-9025-1 |
| Ubuntu 22.04 LTS | linux-raspi | 5.15.0-1113.116 | USN-9029-1 |
| Ubuntu 22.04 LTS | linux-riscv +33 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1080.84 | USN-8875-1 |
Show 16 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 | 6.8.0-2056.58 | USN-9025-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1062.63 | USN-8917-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1109.111 | USN-8875-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1116.125 | USN-8875-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1064.65~22.04.1 | USN-9024-1 |
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1067.70+fips1 | USN-8917-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-147.147+fips1 | USN-8917-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips +1 | 6.8.0-1071.79+fips1 | USN-8918-1, USN-8917-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1117.124+fips1 | USN-8875-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1123.132+fips1 | USN-8875-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-198.208+fips1 | USN-8875-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1118.128+fips1 | USN-8877-1 |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux +10 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1117.124~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1123.132~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1122.131~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1118.128~20.04.1 | USN-8878-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 | 5.15.0-198.208~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 +1 | 5.15.0-1111.115~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1112.118~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-195.205~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1070.72~20.04.1 | USN-8963-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1114.120~20.04.1 | USN-8879-1 |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.78.1 | SUSE-SU-2026:3790-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.78.1.150700.17.43.2 | SUSE-SU-2026:3790-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.37.1 | SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.37.1 | SUSE-SU-2026:23237-1, SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | SUSE-SU-2026:23231-1, SUSE-SU-2026:23221-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | SUSE-SU-2026:23068-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.37.1 | SUSE-SU-2026:23068-1, SUSE-SU-2026:23066-1 |
| SLE Micro 6.1 | kernel-rt +4 | 6.4.0-51.1 | SUSE-SU-2026:23194-1, SUSE-SU-2026:23193-1 |
| SLE Micro 6.0 | kernel-rt +4 | 6.4.0-51.1 | SUSE-SU-2026:23244-1, SUSE-SU-2026:23241-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.78.1 | SUSE-SU-2026:3790-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_19 | 1-150700.1.5.1 | SUSE-SU-2026:3810-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_20 | 1-150700.15.3.2 | SUSE-SU-2026:3790-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.72.1 | SUSE-SU-2026:3810-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 7.1.4-1.1 | openSUSE-SU-2026:11339-1 |
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.37.1.160000.2.19 | openSUSE-SU-2026:21555-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.37.1 | openSUSE-SU-2026:21555-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-206.104.3.3.el10uek | ELSA-2026-500248 |
Advisories 41
- USN-9091-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8875-1 linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-azure, linux-azure-5.15, linux-azure-fde-5.15, linux-azure-fips, linux-fips, linux-gke, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iot-realtime, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-oracle, linux-realtime, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8917-1 linux, linux-aws, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8963-1 linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9024-1 linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8, linux-lowlatency-hwe-6.8, linux-nvidia, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9026-1 linux-azure-6.8, linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-1 linux, linux-aws, linux-aws-7.0, linux-gcp, linux-gke, linux-hwe-7.0, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9029-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9040-1 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8918-1 linux-azure, linux-azure-fde, linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-1 linux-gcp-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-4 linux-azure, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8879-1 linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8760-1 linux-nvidia-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-3 linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-2 linux-azure-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8800-1 linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8878-1 linux-gcp-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-2 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8877-1 linux-gcp, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-3 linux-ibm vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8875-2 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8727-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8760-2 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- WID-SEC-2026-2403 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 12, 2026
- ELSA-2026-500248 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 4, 2026
- SUSE-SU-2026:3810-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 31, 2026
- SUSE-SU-2026:23244-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23231-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23237-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23241-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23221-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:3790-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23194-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 26, 2026
- SUSE-SU-2026:23193-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 26, 2026
- SUSE-SU-2026:23066-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 15, 2026
- SUSE-SU-2026:23068-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 15, 2026
- openSUSE-SU-2026:21555-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 12, 2026
- openSUSE-SU-2026:11339-1 kernel-devel-7.1.4-1.1 on GA media SUSE / openSUSE Security Updates · Jul 23, 2026
References
- https://git.kernel.org/stable/c/35264c4d46067d6312871488c810cef387f8c1f6
- https://git.kernel.org/stable/c/1381b021bf886b793fa5ffb895a8efae7ba0318f
- https://git.kernel.org/stable/c/d08b69da40a101df1e28bfe1e8fa7a09ffa41107
- https://git.kernel.org/stable/c/cd74176cf1685f35a2e5f212d15748bbfecb53b6
- https://git.kernel.org/stable/c/ac229c86e49fdb96d91f51bc2fa37a9c4f58c44f
- https://git.kernel.org/stable/c/7d2a44bc6bbe39aed03c68864aa0e54e04a50278
- https://git.kernel.org/stable/c/585616dab0aa9c45bc11b2c8082ca78533bc00e9
- https://git.kernel.org/stable/c/33ccd52f3cc9ed46ce395199f89aa3234dc83314