CVE-2025-21871: tee: optee: Fix supplicant wait loop
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.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2025-21871?
CVE-2025-21871 is categorized with a medium severity level due to its potential impact on the stability of the Linux kernel.
How do I fix CVE-2025-21871?
To resolve CVE-2025-21871, it is recommended to update to the latest version of the Linux kernel that includes the patch for this vulnerability.
What systems are affected by CVE-2025-21871?
CVE-2025-21871 affects systems running vulnerable versions of the Linux kernel that utilize the OP-TEE supplicant.
What vulnerabilities does CVE-2025-21871 address?
CVE-2025-21871 addresses issues related to the OP-TEE supplicant hanging or crashing during RPC calls, affecting user-space daemon stability.
Is CVE-2025-21871 being actively exploited?
As of the current information available, there are no reports of active exploitation of CVE-2025-21871 in the wild.