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Medium · 5.5 Public exploit CVE-2025-23134 EUVD-2025-11166GHSA-gxg5-6xg7-gc7q

ALSA: timer: Don't take register_mutex with copy_from/to_user()

Published Apr 16, 2025 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux-allwinner-5.19 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-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-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 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-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-edge Package: linux-intel-5.13 Package: linux-intel-iot-realtime 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-nvidia-6.11 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 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-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-raspi-realtime Package: linux-raspi2 Package: linux-realtime 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-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

ALSA: timer: Don't take register_mutex with copy_from/to_user()

The infamous mmap_lock taken in copy_from/to_user() can be often
problematic when it's called inside another mutex, as they might lead
to deadlocks.

In the case of ALSA timer code, the bad pattern is with
guard(mutex)(&register_mutex) that covers copy_from/to_user() -- which
was mistakenly introduced at converting to guard(), and it had been
carefully worked around in the past.

This patch fixes those pieces simply by moving copy_from/to_user() out
of the register mutex lock again.

Affected products

VendorProductAffectedFixed
Linux Linux 6.9 6.12.23

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 ↗
ReleasePackageFixed inAdvisory
Debian 14 linux 6.12.25-1 —
Debian 13 linux 6.12.25-1 —

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.04 linux 6.14.0-22.22 USN-7594-1
Ubuntu 25.04 linux-aws +3 6.14.0-1007.7 USN-7594-3, USN-7594-2, USN-7594-1
Ubuntu 25.04 linux-gcp 6.14.0-1008.8 USN-7594-1
Ubuntu 25.04 linux-realtime 6.14.0-1004.4 USN-7594-1
Ubuntu 24.04 LTS linux-azure-6.11 6.11.0-1018.18~24.04.1 USN-7628-1
Ubuntu 24.04 LTS linux-gcp-6.11 6.11.0-1016.16~24.04.1 USN-7605-1
Ubuntu 24.04 LTS linux-hwe-6.11 6.11.0-28.28~24.04.1 USN-7605-1
Ubuntu 24.04 LTS linux-lowlatency-hwe-6.11 6.11.0-1015.16~24.04.2 USN-7605-2
Ubuntu 24.04 LTS linux-nvidia-6.11 6.11.0-1012.12 —
Ubuntu 24.04 LTS linux-oem-6.11 6.11.0-1024.24 USN-7606-1
Ubuntu 24.04 LTS linux-realtime +1 No fix yet —
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —

SUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.3.1 SUSE-SU-2025:01951-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.3.1 SUSE-SU-2025:01967-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.3.1.150700.17.2.1 SUSE-SU-2025:01951-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.3.1 SUSE-SU-2025:01951-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_1 1-150700.1.3.1 SUSE-SU-2025:01972-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_1 1-150700.15.3.1 SUSE-SU-2025:01951-1
SUSE Real Time Module 15 SP7 kernel-rt +3 6.4.0-150700.7.3.1 SUSE-SU-2025:01972-1

Oracle Linux

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

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • thrilokh-q123/CVE-2025-23134_fixes_code ★ 1 · Sep 20, 2026

    The ASN1_STRING_set() function takes an `int` length, make sure the argument is not inadvertently truncated when it is called from asn1_ex_c2i().

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 13

References