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
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