Improper locking in Linux kernel - CVE-2025-68756

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Main Vulnerability Database Vulnerabilities #VU120960

Improper locking in Linux kernel - CVE-2025-68756

Published: January 5, 2026


Vulnerability identifier: #VU120960
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-68756
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper locking within the blk_mq_quiesce_tagset(), blk_mq_unquiesce_tagset(), blk_mq_del_queue_tag_set() and blk_mq_add_queue_tag_set() functions in block/blk-mq.c. A local user can perform a denial of service (DoS) attack.


Affected software

Linux kernel
Ubuntu
openEuler
python3-perf-debuginfo
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
kernel-source
kernel-extra-modules
linux (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-xilinx (Ubuntu package)
linux-oracle (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gcp-6.17 (Ubuntu package)
linux-realtime-6.17 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-oem-6.17 (Ubuntu package)

How to mitigate CVE-2025-68756

Install update from vendor's repository.

python3-perf-debuginfo - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
bpftool - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
bpftool-debuginfo - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-debuginfo - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-debugsource - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-devel - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-headers - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-tools - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-tools-debuginfo - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-tools-devel - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
perf - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
perf-debuginfo - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
python3-perf - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-source - addressed in versions 6.6.0-144.0.0.127, 6.6.0-144.0.0.139, 6.6.0-144.0.0.140
kernel-extra-modules - update to 6.6.0-144.0.0.140
linux (Ubuntu package) - addressed in versions 6.8.0-110.110, 6.8.0-110.110.1, 6.8.0-110.110.1~22.04.1, 6.8.0-1037.40, 6.8.0-1050.56, 6.8.0-1051.51, 6.8.0-1052.55~22.04.1, 6.8.0-1054.57, 6.17.0-19.19, 6.17.0-19.19~24.04.2, 6.17.0-1009.9, 6.17.0-1009.9~24.04.1, 6.17.0-1009.9~24.04.2
linux-aws-fips (Ubuntu package) - addressed in versions 6.8.0-110.110+fips2, 6.8.0-1052.55+fips1, 6.8.0-1054.57+fips1
linux-hwe-6.8 (Ubuntu package) - addressed in versions 6.8.0-110.110~22.04.1, 6.8.0-1051.51~22.04.1, 6.8.0-1052.56
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1022.22
linux-xilinx (Ubuntu package) - update to 6.8.0-1029.30
linux-oracle (Ubuntu package) - addressed in versions 6.8.0-1049.50, 6.8.0-1049.50~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1051.54, 6.8.0-1051.54~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1051.54.1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1054.60, 6.17.0-1010.10, 6.17.0-1010.10~24.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1054.60+fips1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2042.43
linux-realtime (Ubuntu package) - update to 6.8.1-1047.48
linux-gcp-6.17 (Ubuntu package) - addressed in versions 6.17.0-1008.9, 6.17.0-1009.9~24.04.3
linux-realtime-6.17 (Ubuntu package) - update to 6.17.0-1008.9~24.04.1
linux-raspi (Ubuntu package) - update to 6.17.0-1010.10
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1017.17

External References

Related Security Bulletins