Improper locking in Linux kernel - CVE-2025-68823
Published: January 14, 2026
Vulnerability identifier: #VU121402
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-2025-68823
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 ublk_get_uring_cmd_pdu(), __ublk_complete_rq(), __ublk_abort_rq() and __ublk_do_auto_buf_reg() functions in drivers/block/ublk_drv.c. A local user can perform a denial of service (DoS) attack.
Affected software
Linux kernel
Debian Linux
Ubuntu
linux-fips (Ubuntu package)
linux (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux (Debian package)
linux-aws (Ubuntu package)
linux-realtime-6.17 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-raspi (Ubuntu package)
Debian Linux
Ubuntu
linux-fips (Ubuntu package)
linux (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux (Debian package)
linux-aws (Ubuntu package)
linux-realtime-6.17 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-raspi (Ubuntu package)
How to mitigate CVE-2025-68823
Install update from vendor's repository.
linux-fips (Ubuntu package) - update to 6.8.0-116.116+fips1
linux (Ubuntu package) - addressed in versions 6.8.0-117.117, 6.8.0-117.117.1, 6.8.0-117.117.1~22.04.1, 6.8.0-1041.44, 6.8.0-1054.60, 6.8.0-1055.56, 6.8.0-1055.56~22.04.1, 6.8.0-1055.58+fips1, 6.8.0-1056.60, 6.8.0-1058.61, 6.8.0-1058.61+fips1, 6.8.0-2045.46, 6.8.1-1051.52, 6.8.1-1051.52~22.04.1, 6.17.0-22.22, 6.17.0-1010.11
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1024.24
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1054.57, 6.8.0-1054.57.1
linux-nvidia-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1056.62, 6.17.0-1013.13, 6.17.0-1013.13~24.04.1, 6.17.0-1020.20
linux (Debian package) - update to 6.12.73-1
linux-aws (Ubuntu package) - addressed in versions 6.17.0-22.22~24.04.1, 6.17.0-1011.11, 6.17.0-1011.11~24.04.1, 6.17.0-1012.12, 6.17.0-1012.12~24.04.1
linux-realtime-6.17 (Ubuntu package) - update to 6.17.0-1010.11~24.04.1
linux-gcp (Ubuntu package) - addressed in versions 6.17.0-1012.12, 6.17.0-1012.12~24.04.1
linux-raspi (Ubuntu package) - update to 6.17.0-1014.14
linux (Ubuntu package) - addressed in versions 6.8.0-117.117, 6.8.0-117.117.1, 6.8.0-117.117.1~22.04.1, 6.8.0-1041.44, 6.8.0-1054.60, 6.8.0-1055.56, 6.8.0-1055.56~22.04.1, 6.8.0-1055.58+fips1, 6.8.0-1056.60, 6.8.0-1058.61, 6.8.0-1058.61+fips1, 6.8.0-2045.46, 6.8.1-1051.52, 6.8.1-1051.52~22.04.1, 6.17.0-22.22, 6.17.0-1010.11
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1024.24
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1054.57, 6.8.0-1054.57.1
linux-nvidia-6.8 (Ubuntu package) - update to 6.8.0-1054.57~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1056.62, 6.17.0-1013.13, 6.17.0-1013.13~24.04.1, 6.17.0-1020.20
linux (Debian package) - update to 6.12.73-1
linux-aws (Ubuntu package) - addressed in versions 6.17.0-22.22~24.04.1, 6.17.0-1011.11, 6.17.0-1011.11~24.04.1, 6.17.0-1012.12, 6.17.0-1012.12~24.04.1
linux-realtime-6.17 (Ubuntu package) - update to 6.17.0-1010.11~24.04.1
linux-gcp (Ubuntu package) - addressed in versions 6.17.0-1012.12, 6.17.0-1012.12~24.04.1
linux-raspi (Ubuntu package) - update to 6.17.0-1014.14
External References
Related Security Bulletins
- Improper locking in Linux kernel block driver
- Debian update for linux
- Ubuntu update for linux
- Ubuntu update for linux-realtime-6.17
- Ubuntu update for linux-gcp
- Ubuntu update for linux-aws
- Ubuntu update for linux-azure
- Ubuntu update for linux-raspi
- Ubuntu update for linux
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-fips
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-nvidia-6.8
- Ubuntu update for linux-azure