CVE-2025-68368: Linux kernel · md: init bioset in mddev_init
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.17.0-1012.12~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-1012.12~24.04.1, 6.17.0-1013.13~24.04.1, 6.17.0-22.22~24.04.1 +11
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Dec 2025
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.
Patches and advisories
- 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)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?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.
Description
In the Linux kernel, the following vulnerability has been resolved: md: init bioset in mddev_init IO operations may be needed before md_run(), such as updating metadata after writing sysfs. Without bioset, this triggers a NULL pointer dereference as below: BUG: kernel NULL pointer dereference, address: 0000000000000020 Call Trace: md_update_sb+0x658/0xe00 new_level_store+0xc5/0x120 md_attr_store+0xc9/0x1e0 sysfs_kf_write+0x6f/0xa0 kernfs_fop_write_iter+0x141/0x2a0 vfs_write+0x1fc/0x5a0 ksys_write+0x79/0x180 __x64_sys_write+0x1d/0x30 x64_sys_call+0x2818/0x2880 do_syscall_64+0xa9/0x580 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Reproducer ``` mdadm -CR /dev/md0 -l1 -n2 /dev/sd[cd] echo inactive > /sys/block/md0/md/array_state echo 10 > /sys/block/md0/md/new_level ``` mddev_init() can only be called once per mddev, no need to test if bioset has been initialized anymore.
References
- ubuntu.com/security/CVE-2025-68368 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68368 (opens in a new tab)
- git.kernel.org/stable/c/381a3ce1c0ffed647c9b913e142b099c7e9d5afc (opens in a new tab)
- git.kernel.org/stable/c/9d37fe37dfa0833a8768740f0575e0ffd793cb4a (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)