Improper locking in Linux kernel - CVE-2025-40327

Vulnerability identifier: #VU119740

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-2025-40327

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to improper locking within the perf_swevent_hrtimer(), perf_swevent_cancel_hrtimer(), cpu_clock_event_update() and task_clock_event_update() functions in kernel/events/core.c. A local user can perform a denial of service (DoS) attack.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-oem-6.17 (Ubuntu package)

Install update from vendor's repository.

linux (Ubuntu package) - addressed in versions 6.17.0-14.14, 6.17.0-1006.7, 6.17.0-1008.8
linux-gcp (Ubuntu package) - update to 6.17.0-1007.7
linux-aws (Ubuntu package) - update to 6.17.0-1007.7
linux-azure (Ubuntu package) - update to 6.17.0-1008.8
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1011.11

• https://git.kernel.org/stable/c/6b8c512811644cf2f5eaf6f44e928683c54127f0
• https://git.kernel.org/stable/c/eb3182ef0405ff2f6668fd3e5ff9883f60ce8801

• Improper locking in Linux kernel events
• Ubuntu update for linux-gcp
• Ubuntu update for linux
• Ubuntu update for linux-aws
• Ubuntu update for linux-oem-6.17
• Ubuntu update for linux-azure