Hi!
commit f8502fba45bd30e1a6a354d9d898bc99d1a11e6d upstream.
There is a potential race condition in amdtee_open_session that may lead to use-after-free. For instance, in amdtee_open_session() after sess->sess_mask is set, and before setting:
sess->session_info[i] = session_info;if amdtee_close_session() closes this same session, then 'sess' data structure will be released, causing kernel panic when 'sess' is accessed within amdtee_open_session().
The solution is to set the bit sess->sess_mask as the last step in amdtee_open_session().
Ok, but:
+++ b/drivers/tee/amdtee/core.c @@ -267,35 +267,34 @@ int amdtee_open_session(struct tee_conte goto out; }
- /* Open session with loaded TA */
- handle_open_session(arg, &session_info, param);
- if (arg->ret != TEEC_SUCCESS) {
pr_err("open_session failed %d\n", arg->ret);handle_unload_ta(ta_handle);kref_put(&sess->refcount, destroy_session);goto out;- }
rc needs to be set to something here, otherwise we'll return 0 below.
out: free_pages((u64)ta, get_order(ta_size)); return rc;
Best regards, Pavel