CVE-2025-21871: Linux kernel · tee: optee: Fix supplicant wait loop
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 29 Oct 2026, 22:52 UTC
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 27 Mar 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 29 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: tee: optee: Fix supplicant wait loop OP-TEE supplicant is a user-space daemon and it's possible for it be hung or crashed or killed in the middle of processing an OP-TEE RPC call. It becomes more complicated when there is incorrect shutdown ordering of the supplicant process vs the OP-TEE client application which can eventually lead to system hang-up waiting for the closure of the client application. Allow the client process waiting in kernel for supplicant response to be killed rather than indefinitely waiting in an unkillable state. Also, a normal uninterruptible wait should not have resulted in the hung-task watchdog getting triggered, but the endless loop would. This fixes issues observed during system reboot/shutdown when supplicant got hung for some reason or gets crashed/killed which lead to client getting hung in an unkillable state. It in turn lead to system being in hung up state requiring hard power off/on to recover.
References
- nvd.nist.gov/vuln/detail/CVE-2025-21871 (opens in a new tab)
- git.kernel.org/stable/c/0180cf0373f84fff61b16f8c062553a13dd7cfca (opens in a new tab)
- git.kernel.org/stable/c/21234efe2a8474a6d2d01ea9573319de7858ce44 (opens in a new tab)
- git.kernel.org/stable/c/3eb4911364c764572e9db4ab900a57689a54e8ce (opens in a new tab)
- git.kernel.org/stable/c/70b0d6b0a199c5a3ee6c72f5e61681ed6f759612 (opens in a new tab)
- git.kernel.org/stable/c/c0a9a948159153be145f9471435695373904ee6d (opens in a new tab)
- git.kernel.org/stable/c/d61cc1a435e6894bfb0dd3370c6f765d2d12825d (opens in a new tab)
- git.kernel.org/stable/c/ec18520f5edc20a00c34a8c9fdd6507c355e880f (opens in a new tab)
- git.kernel.org/stable/c/fd9d2d6124c293e40797a080adf8a9c237efd8b8 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html (opens in a new tab)