tee: amdtee: fix use-after-free vulnerability in amdtee_close_session
commit f4384b3e upstream. There is a potential race condition in amdtee_close_session that may cause use-after-free in amdtee_open_session. For instance, if a session has refcount == 1, and one thread tries to free this session via: kref_put(&sess->refcount, destroy_session); the reference count will get decremented, and the next step would be to call destroy_session(). However, if in another thread, amdtee_open_session() is called before destroy_session() has completed execution, alloc_session() may return 'sess' that will be freed up later in destroy_session() leading to use-after-free in amdtee_open_session. To fix this issue, treat decrement of sess->refcount and removal of 'sess' from session list in destroy_session() as a critical section, so that it is executed atomically. Fixes: 757cc3e9 ("tee: add AMD-TEE driver") Cc: stable@vger.kernel.org Signed-off-by:Rijo Thomas <Rijo-john.Thomas@amd.com> Reviewed-by:
Sumit Garg <sumit.garg@linaro.org> Signed-off-by:
Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
862aa981
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