CVE-2025-68823: Linux kernel · ublk: fix deadlock when reading partition table
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1057.60~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1057.60~22.04.1, 6.8.0-1059.65~22.04.1, 6.8.0-1060.63~22.04.1 +41
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-22.22?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1012.12?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1013.13?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1012.12?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1011.11?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied. The fix involves running blk_update_request() and blk_mq_end_request() with bottom halves disabled to avoid the deadlock. Users should update to patched Linux kernel versions as provided by their vendor. After updating, a system reboot is required to apply the fix. No additional mitigation steps are indicated by the vendor advisory.
Description
A deadlock vulnerability in the Linux kernel's ublk userspace block driver was fixed. The issue occurs when a process such as udev opens a ublk block device to read the partition table, leading to a deadlock due to recursive locking of disk->open_mutex. The fix involves running certain request completion functions with bottom halves disabled to avoid the deadlock. This vulnerability affects specific Linux kernel versions and has a medium severity rating with a CVSS score of 5.5.
References
- ubuntu.com/security/CVE-2025-68823 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68823 (opens in a new tab)
- git.kernel.org/linus/c258f5c4502c9667bccf5d76fa731ab9c96687c1 (opens in a new tab)
- git.kernel.org/stable/c/0460e09a614291f06c008443f47393c37b7358e7 (opens in a new tab)
- git.kernel.org/stable/c/c258f5c4502c9667bccf5d76fa731ab9c96687c1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8177-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8177-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8183-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8183-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8245-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8257-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8440-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)