Description
In the Linux kernel, the following vulnerability has been resolved:
ufs: validate cylinder group metadata before caching it
ufs_read_cylinder() copies the cylinder group index and the rotor
positions straight from the on-disk group and caches them without any
check:
ucpi->c_cgx = fs32_to_cpu(sb, ucg->cg_cgx);
ucpi->c_rotor = fs32_to_cpu(sb, ucg->cg_rotor);
ucpi->c_frotor = fs32_to_cpu(sb, ucg->cg_frotor);
ucpi->c_irotor = fs32_to_cpu(sb, ucg->cg_irotor);
They are then used as indices during allocation and free:
- c_cgx indexes the cylinder summary array as
UFS_SB(sb)->fs_cs(ucpi->c_cgx), so a value past s_ncg writes a 32
bit count outside the s_csp allocation.
- c_frotor becomes a bitmap scan start, start = c_frotor >> 3, and
then length = ((s_fpg + 7) >> 3) - start. A start beyond the block
bitmap wraps the unsigned length to a huge value, so ubh_scanc()
walks far past the cylinder group buffers. c_irotor drives the
inode bitmap the same way.
A crafted image can set any of these freely, turning an ordinary
allocation into an out of bounds access.
Reject a cylinder group whose recorded index does not match the group
being read, or whose rotors fall outside the group, before the metadata
is cached. Valid filesystems keep cg_cgx equal to the group number and
the rotors within the group, so only malformed images are rejected.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 2.6.12 | 5.10.271 |
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 | 7.2.7-1 | — |
| Debian 13 | linux | 6.12.111-1 | — |
| Debian 12 | linux | 6.1.190-1 | — |
| Debian 12 | linux-6.12 | 6.12.111-1~deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1036.41 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1103.105 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-42.42 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-aws | 7.0.0-1016.17 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1020.21 | USN-9019-1 |
| Ubuntu 26.04 LTS | linux-azure-fde | 7.0.0-1019.19 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-gcp | 7.0.0-1016.18 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1010.11 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1017.17 | USN-8960-1, USN-8959-1 |
| Ubuntu 26.04 LTS | linux-nvidia +1 | No fix yet | — |
| Ubuntu 26.04 LTS | linux-oracle | 7.0.0-1015.16 | USN-8959-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1023.23 | USN-9021-1 |
| Ubuntu 26.04 LTS | linux-realtime | 7.0.0-43.43.1 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-riscv | 7.0.0-42.42.1 | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-149.149 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1069.74 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 | 7.0.0-1017.18~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1073.82 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1071.78 | USN-9039-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1019.19~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1073.81 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-gcp-7.0 | 7.0.0-1017.19~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1068.77 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1053.57 | USN-9023-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-42.42~24.04.1 | USN-8959-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1069.70 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-149.149.1 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1067.70 | USN-9024-1 |
| 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 | 6.8.0-1067.71 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-oracle-7.0 | 7.0.0-1016.18~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1068.72 | USN-9025-1 |
| Ubuntu 24.04 LTS | linux-riscv +31 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-42.42.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1010.10 | USN-9022-1 |
| Ubuntu 22.04 LTS | linux | 5.15.0-202.212 | USN-8961-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1119.126 | USN-8961-1 |
| 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 | 5.15.0-1125.134 | USN-8961-1 |
| 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 | 5.15.0-1124.133 | USN-8962-1 |
| 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 | 5.15.0-1120.130 | USN-8961-1 |
| 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 | 5.15.0-1115.121 | USN-8961-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1102.110 | USN-8961-1 |
| 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 | 5.15.0-1113.117 | USN-8961-1 |
| 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 | 5.15.0-1114.120 | USN-8961-1 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1111.116 | USN-8961-1 |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-197.207 | USN-8961-1 |
| 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 | 5.15.0-1114.115 | USN-8961-1 |
| 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 | 5.15.0-1116.122 | USN-8961-1 |
| 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 +34 | No fix yet | — |
Show 18 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 | 6.8.1-1064.65 | USN-9023-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1111.115 | USN-8961-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1118.127 | USN-8961-1 |
| 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 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1069.74+fips1 | USN-9023-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1073.82+fips1 | USN-9022-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1073.81+fips1 | USN-9023-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1119.126+fips1 | USN-8961-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1125.134+fips1 | USN-8961-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-202.212+fips1 | USN-8961-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1120.130+fips1 | USN-8961-1 |
| 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-updates 16.04 LTS | linux-fips | 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 | 5.15.0-1119.126~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1125.134~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1124.133~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1120.130~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 | 5.15.0-202.212~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 | 5.15.0-1113.117~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1114.120~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-197.207~20.04.1 | USN-8961-1 |
| 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 | 5.15.0-1116.122~20.04.1 | USN-8961-1 |
| Ubuntu Pro 20.04 LTS | linux-riscv-5.15 | 5.15.0-1113.117~20.04.2 | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux +3 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.90.1 | SUSE-SU-2026:5091-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.90.1.150700.17.51.1 | SUSE-SU-2026:5091-1 |
| SLES 12 SP5 | kernel-syms +2 | 4.12.14-122.339.1 | SUSE-SU-2026:5121-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.90.1 | SUSE-SU-2026:5091-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_24 | 1-150700.15.3.1 | SUSE-SU-2026:5091-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.339.1 | SUSE-SU-2026:5121-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_90 | 1-8.3.1 | SUSE-SU-2026:5121-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 7.2.9-1.1 | openSUSE-SU-2026:12074-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.158.1-1 | — |
Advisories 22
- USN-9091-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8961-1 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-gcp, linux-gcp-5.15, linux-gcp-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-nvidia, linux-oracle, linux-oracle-5.15, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9020-1 linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0, linux-gcp-7.0, linux-gke, linux-oracle-7.0, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8959-1 linux, linux-aws, linux-gcp, linux-hwe-7.0, linux-ibm, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9022-1 linux, linux-aws, linux-azure, linux-azure-fips, linux-gcp, linux-gke, linux-ibm, linux-lowlatency, linux-oracle, linux-vmware 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-9023-1 linux-aws-fips, linux-gcp-fips, linux-gkeop, linux-realtime 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-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9039-1 linux-azure-fde 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-9019-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8960-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8962-1 linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- WID-SEC-2026-3579 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:5121-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 6, 2026
- SUSE-SU-2026:5091-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 4, 2026
- openSUSE-SU-2026:12074-1 kernel-devel-7.2.9-1.1 on GA media SUSE / openSUSE Security Updates · Oct 9, 2026
References
- https://git.kernel.org/stable/c/88cccb6beba136b73f0caf80e59457e1b3c0ca1e
- https://git.kernel.org/stable/c/f560a9e33365c460827c735fd86435f9213f1aed
- https://git.kernel.org/stable/c/e4c5cc9688c3e69d07d888853388549ae26c0521
- https://git.kernel.org/stable/c/58c0c414b2b8d099d33da494a354fa836ca6c10b
- https://git.kernel.org/stable/c/5902a95066883cf96fa15b2680694fc5dd0c7d11
- https://git.kernel.org/stable/c/87b12dc360a002eb2d498aa4f01e84347019612d
- https://git.kernel.org/stable/c/abde9eb33106850dfa367ad3965d3588bb8558d5
- https://git.kernel.org/stable/c/c9d263be26806d388129fab8c6904bed197fc6af