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OpenAdvisories
Medium · 5.5 CVE-2025-21672 EUVD-2025-2621GHSA-94vp-7849-58r6

afs: Fix merge preference rule failure condition

Published Jan 31, 2025 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-nvidia Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

afs: Fix merge preference rule failure condition

syzbot reported a lock held when returning to userspace[1]. This is
because if argc is less than 0 and the function returns directly, the held
inode lock is not released.

Fix this by store the error in ret and jump to done to clean up instead of
returning directly.

[dh: Modified Lizhi Xu's original patch to make it honour the error code
from afs_split_string()]

[1]
WARNING: lock held when returning to user space!
6.13.0-rc3-syzkaller-00209-g499551201b5f #0 Not tainted
------------------------------------------------
syz-executor133/5823 is leaving the kernel with locks still held!
1 lock held by syz-executor133/5823:
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: afs_proc_addr_prefs_write+0x2bb/0x14e0 fs/afs/addr_prefs.c:388

Affected products

VendorProductAffectedFixed
Linux Linux 6.8 6.12.11

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.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.12.11-1 —
Debian 13 linux 6.12.11-1 —
ReleasePackageFixed inAdvisory
Ubuntu 24.04 LTS linux 6.8.0-62.65 USN-7595-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1030.32 USN-7595-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1030.35 USN-7596-1
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1018.19 USN-7596-2
Ubuntu 24.04 LTS linux-gcp 6.8.0-1031.33 USN-7595-5
Ubuntu 24.04 LTS linux-gcp-6.11 +1 6.11.0-1013.13~24.04.1 USN-7448-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1026.30 USN-7595-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1013.15 USN-7595-1
Ubuntu 24.04 LTS linux-hwe-6.11 6.11.0-24.24~24.04.1 USN-7445-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1027.27 USN-7595-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-62.65.1 USN-7595-1
Ubuntu 24.04 LTS linux-lowlatency-hwe-6.11 6.11.0-1012.13~24.04.1 USN-7445-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1029.32 USN-7595-1
Ubuntu 24.04 LTS linux-nvidia-6.11 6.11.0-1007.7 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1029.32.1 USN-7595-1
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1008.8 —
Ubuntu 24.04 LTS linux-oem-6.11 6.11.0-1020.20 USN-7445-1
Ubuntu 24.04 LTS linux-oem-6.8 6.8.0-1029.29 USN-7595-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1027.28 USN-7595-4
Ubuntu 24.04 LTS linux-raspi 6.8.0-1029.33 USN-7595-4
Ubuntu 24.04 LTS linux-riscv +2 No fix yet —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1017.18 —
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1030.32~22.04.1 USN-7595-1
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1030.35~22.04.1 USN-7596-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1031.33~22.04.1 USN-7595-5
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-64.67~22.04.1 USN-7653-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1027.27~22.04.1 —
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-62.65.1~22.04.1 USN-7595-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1029.32~22.04.1 USN-7595-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1027.28~22.04.1 USN-7595-4
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 6.8.0-62.65~22.04.1 —
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 —
Show 3 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2024.25 USN-7595-3
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1023.24 USN-7595-2
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1023.24~22.04.1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-78.78+fips1 —
ReleasePackageFixed inAdvisory
RHEL 9 rv +75 5.14.0-611.5.1.el9_7 RHSA-2025:20518

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 9 rv +73 5.14.0-611.5.1.el9_7 ALSA-2025:20518

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 9 kernel 5.14.0-611.5.1.el9_7 RLSA-2025:20518

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel No fix yet —
Azure Linux 2 (CBL-Mariner) kernel No fix yet —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-101.33.4.3.el10uek ELSA-2025-20530, ELSA-2025-20480

Advisories 17

References