CVE-2025-21951: Linux kernel · bus: mhi: host: pci_generic: Use pci_try_reset_function() to avoid deadlock
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1084.91~20.04.1 : update Linux kernel when convenient.
Data as of 12 Nov 2026, 19:33 UTC
- Patch
- Available – fixed in 5.15.0-1084.91~20.04.1, 5.15.0-1089.98~20.04.1, 5.15.0-1083.92~20.04.1 +66
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 1 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7510-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7512-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-7 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-8 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther 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 included in Linux kernel versions 5.15.0-1076.79~20.04.1 and later listed fixed versions. Users should update to one of these fixed kernel versions to remediate the issue. After updating, a system reboot is required to apply the fix. No additional mitigation actions are necessary as the patch addresses the root cause.
Description
A deadlock vulnerability in the Linux kernel's PCI generic host driver (bus: mhi: host: pci_generic) was fixed by changing the device reset method to pci_try_reset_function(). The issue occurs when recovery work tries to reset a device while the device_lock() is already held by the caller, causing a deadlock during shutdown or suspend callbacks. This was observed on the X1E80100 CRD device but may affect other devices using similar code paths. The fix avoids deadlock by attempting to acquire the lock without blocking and failing gracefully if the lock is unavailable.
References
- ubuntu.com/security/CVE-2025-21951 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21951 (opens in a new tab)
- git.kernel.org/linus/a321d163de3d8aa38a6449ab2becf4b1581aed96 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7512-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-7 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-8 (opens in a new tab)
- ubuntu.com/security/notices/USN-7593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7602-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-2 (opens in a new tab)