linux/drivers/tee
Amirreza Zarrabi 724d0caffd tee: optee: prevent use-after-free when the client exits before the supplicant
[ Upstream commit 387a926ee1 ]

Commit 70b0d6b0a1 ("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.

Fixes: 70b0d6b0a1 ("tee: optee: Fix supplicant wait loop")
Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
Tested-by: Ox Yeh <ox.yeh@mediatek.com>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2026-06-19 13:33:32 +02:00
..
amdtee tee: amdtee: fix use-after-free vulnerability in amdtee_close_session 2023-10-19 23:05:37 +02:00
optee tee: optee: prevent use-after-free when the client exits before the supplicant 2026-06-19 13:33:32 +02:00
Kconfig tee: fix crypto select 2020-05-28 12:38:00 +02:00
Makefile tee: add AMD-TEE driver 2020-01-04 13:49:51 +08:00
tee_core.c tee: allow a driver to allocate a tee_device without a pool 2025-12-07 06:09:17 +09:00
tee_private.h tee: don't assign shm id for private shms 2020-02-28 13:37:42 +01:00
tee_shm.c tee: fix NULL pointer dereference in tee_shm_put 2025-09-09 18:50:17 +02:00
tee_shm_pool.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00