CVE-2025-21871

MEDIUMCVSS 5.5/10EPSS 0.17%

Last modified

CVE-2025-21871 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.17%

7.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 4.12, < 5.4.291
LinuxLinux Kernel>= 5.5, < 5.10.235
LinuxLinux Kernel>= 5.11, < 5.15.179
LinuxLinux Kernel>= 5.16, < 6.1.130
LinuxLinux Kernel>= 6.2, < 6.6.80
LinuxLinux Kernel>= 6.7, < 6.12.17
LinuxLinux Kernel>= 6.13, < 6.13.5
LinuxLinux Kernel6.14Rc1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2025-21871?
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.
How severe is CVE-2025-21871?
CVE-2025-21871 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2025-21871?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-21871?

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Source: NVD / NIST