CVE-2025-21871
MediumIn 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.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-835CVE-2025-21871 is a Infinite Loop vulnerability
What is Infinite Loop?
The product contains an iteration that does not exit even when it should. Learn more on MITRE CWE
Affected versions
Linux kernel versions
4.12
and later are affected. Fixed in
5.4.291,
5.10.235,
5.15.179,
6.1.130,
6.6.80,
6.12.17,
6.13.5,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21871 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/0180cf0373f84fff61b16f8c062553a13dd7cfca
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PatchKernel patch commithttps://git.kernel.org/stable/c/21234efe2a8474a6d2d01ea9573319de7858ce44
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PatchKernel patch commithttps://git.kernel.org/stable/c/3eb4911364c764572e9db4ab900a57689a54e8ce
Frequently asked questions
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What is CVE-2025-21871?
CVE-2025-21871 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Infinite Loop flaw (CWE-835) . It affects Linux kernel versions from 4.12 onward and has been patched in 5.4.291, 5.10.235, 5.15.179 and others. CVE-2025-21871 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2025-21871?
CVE-2025-21871 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-21871?
Yes — CVE-2025-21871 has been patched. Fixed versions include 5.4.291, 5.10.235, 5.15.179 and others. If you are running Linux kernel 4.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21871 actively exploited?
No — CVE-2025-21871 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Infinite Loop (CWE-835)?
The product contains an iteration that does not exit even when it should. View CWE-835 on MITRE CWE →