CVE-2025-21912: Linux kernel · gpio: rcar: Use raw_spinlock to protect register access
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 28 Oct 2026, 12:58 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 +67
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
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-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 5.15.0-1084.91 and later. Users should update their Linux kernel to a fixed version to remediate this vulnerability. After updating, a system reboot is required to apply the fix. No additional mitigation actions are necessary as the issue is resolved by the official kernel update.
Description
CVE-2025-21912 is a vulnerability in the Linux kernel's gpio subsystem for Renesas R-Car platforms. It involves improper locking of register access, which caused spurious invalid context messages when spinlock debugging is enabled. The issue was fixed by using raw_spinlock to serialize register access properly. This vulnerability affects multiple Linux kernel versions prior to 5.15.0-1084.91 and similar builds. The flaw does not impact confidentiality or integrity but can cause denial of service due to kernel instability.
References
- ubuntu.com/security/CVE-2025-21912 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21912 (opens in a new tab)
- git.kernel.org/linus/f02c41f87cfe61440c18bf77d1ef0a884b9ee2b5 (opens in a new tab)
- git.kernel.org/stable/c/3e300913c42041e81c5b17a970c4e078086ff2d1 (opens in a new tab)
- git.kernel.org/stable/c/51ef3073493e2a25dced05fdd59dfb059e7e284d (opens in a new tab)
- git.kernel.org/stable/c/7c1f36f9c9aca507d317479a3d3388150ae40a87 (opens in a new tab)
- git.kernel.org/stable/c/b42c84f9e4ec5bc2885e7fd80c79ec0352f5d2af (opens in a new tab)
- git.kernel.org/stable/c/c10365031f16514a29c812cd909085a6e4ea4b61 (opens in a new tab)
- git.kernel.org/stable/c/f02c41f87cfe61440c18bf77d1ef0a884b9ee2b5 (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)