CVE-2026-53273
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile — higher than 3% of all known CVEs
Summary
A use-after-free vulnerability was found in the Linux kernel's TEE OP-TEE driver. The issue occurs when the client exits before the supplicant, causing a race condition and use of freed memory.
Risk Assessment
An attacker could exploit this vulnerability to gain unauthorized access to kernel memory, potentially leading to privilege escalation or data leakage.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit 70b0d6b0a199 or later).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: tee: optee: prevent use-after-free when the client exits before the supplicant Commit 70b0d6b0a199 ("tee: optee: Fix supplicant wait loop") made the client wait as killable so it can be interrupted during shutdown or after a supplicant crash. This changes the original lifetime expectations: the client task can now terminate while the supplicant is still processing its request. If the client exits first it removes the request from its queue and kfree()s it, while the request ID remains in supp->idr. A subsequent lookup on the supplicant path then dereferences freed memory, leading to a use-after-free. Serialise access to the request with supp->mutex: * Hold supp->mutex in optee_supp_recv() and optee_supp_send() while looking up and touching the request. * Let optee_supp_thrd_req() notice that the client has terminated and signal optee_supp_send() accordingly. With these changes the request cannot be freed while the supplicant still has a reference, eliminating the race.