Description
In the Linux kernel, the following vulnerability has been resolved:
loop: Avoid updating block size under exclusive owner
Syzbot came up with a reproducer where a loop device block size is
changed underneath a mounted filesystem. This causes a mismatch between
the block device block size and the block size stored in the superblock
causing confusion in various places such as fs/buffer.c. The particular
issue triggered by syzbot was a warning in __getblk_slow() due to
requested buffer size not matching block device block size.
Fix the problem by getting exclusive hold of the loop device to change
its block size. This fails if somebody (such as filesystem) has already
an exclusive ownership of the block device and thus prevents modifying
the loop device under some exclusive owner which doesn't expect it.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.14 | 6.1.191 |
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 | 6.16.3-1 | — |
| Debian 13 | linux | 6.12.43-1 | — |
| Debian 12 | linux | No fix yet | — |
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 | No fix yet | — |
| 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 +49 | No fix yet | — |
| 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-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1052.55~22.04.1 | USN-8095-1 |
| 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-6.8 | 6.8.0-1049.49~22.04.1 | USN-8095-1 |
| 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-6.8 | 6.8.0-1049.52~22.04.1 | USN-8100-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1047.48~22.04.1 | USN-8095-1 |
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 | 6.8.0-2040.41 | 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-realtime +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1045.46~22.04.1 | USN-8095-3 |
| 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 | 6.8.0-1050.53+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-fips +3 | No fix yet | — |
| 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 +21 | No fix yet | — |
| 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 +6 | 6.4.0-150700.53.19.1 | SUSE-SU-2025:03601-1 |
| SLES 15 SP7 | kernel-azure +1 | 6.4.0-150700.20.15.2 | SUSE-SU-2025:03633-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.19.1.150700.17.13.1 | SUSE-SU-2025:03601-1 |
| SLES 15 SP7 | kernel-syms-azure | 6.4.0-150700.20.15.1 | SUSE-SU-2025:03633-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| SLES 15 SP6 | kernel-coco +3 | 6.4.0-15061.32.coco15sp6.1 | SUSE-SU-2025:03602-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21139-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21179-1, SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21074-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.6.1 | SUSE-SU-2026:20560-1, SUSE-SU-2025:21074-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20898-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20851-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20870-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20851-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.19.1 | SUSE-SU-2025:03601-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_5 | 1-150700.1.3.1 | SUSE-SU-2025:3725-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_5 | 1-150700.15.3.1 | SUSE-SU-2025:03601-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_16 | 1-150600.1.3.1 | SUSE-SU-2025:3751-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_16 | 1-150600.13.3.1 | SUSE-SU-2025:03600-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.19.1 | SUSE-SU-2025:3725-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 16.0 | kernel-rt +10 | 6.12.0-160000.6.1 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.46-66.121 | 1:1.0-0.amzn2023 | ALAS2023-2025-1208 |
| 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 3 | kernel | 6.6.104.2-1 | — |
| Azure Linux 2 (CBL-Mariner) | kernel | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-104.43.4.2.el10uek | ELSA-2025-20662 |
Advisories 29
- WID-SEC-2025-1976 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service 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-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-8261-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- SUSE-SU-2026:20560-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- openSUSE-SU-2025:20081-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21139-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21074-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20851-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03634-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20861-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03602-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20870-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03600-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03633-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03601-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20898-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:3751-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:3725-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2025-1208 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 18, 2025
- ELSA-2025-20662 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 14, 2025
References
- https://git.kernel.org/stable/c/46034518cae95db4abfde990c9ca1a0751855072
- https://git.kernel.org/stable/c/457d2c5e112fd08dc1039b1ae39a83ec1782360d
- https://git.kernel.org/stable/c/139a000d20f2f38ce34296feddd641d730fe1c08
- https://git.kernel.org/stable/c/b928438cc87c0bf7ae078e4b7b6e14261e84c5c5
- https://git.kernel.org/stable/c/5d67b30aefeb7a949040bbb1b4e3b84c5d29a624
- https://git.kernel.org/stable/c/7e49538288e523427beedd26993d446afef1a6fb