From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6C9B8476 for ; Tue, 28 Mar 2023 14:54:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 684B1C4339B; Tue, 28 Mar 2023 14:54:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680015268; bh=auzT78B8sTYFbmdAMJSvXW38zALVULSPkuQHYRo5wJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l/FQuIMqHRy4fIwa2BuHBtqy+Ky1tJ+mfhqLS74qgkMlnyZ7oFUoYyl6RRWe2bM8X xAf1nkbOUEuwmG/WSz0yQjJwMuwIqpdOCG15CgPQTvmJN4fqLAa98ZXhaA9OvD5Jts RL6eNDZ13BoUNvgcG2E+uB6g+n48DetSDBvJXMKo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Rijo Thomas , Sumit Garg , Jens Wiklander Subject: [PATCH 6.2 227/240] tee: amdtee: fix race condition in amdtee_open_session Date: Tue, 28 Mar 2023 16:43:10 +0200 Message-Id: <20230328142629.187600434@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230328142619.643313678@linuxfoundation.org> References: <20230328142619.643313678@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Rijo Thomas 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(). Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver") Cc: stable@vger.kernel.org Signed-off-by: Rijo Thomas Acked-by: Sumit Garg Signed-off-by: Jens Wiklander Signed-off-by: Greg Kroah-Hartman --- drivers/tee/amdtee/core.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) --- a/drivers/tee/amdtee/core.c +++ 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; + } + /* Find an empty session index for the given TA */ spin_lock(&sess->lock); i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS); - if (i < TEE_NUM_SESSIONS) + if (i < TEE_NUM_SESSIONS) { + sess->session_info[i] = session_info; + set_session_id(ta_handle, i, &arg->session); set_bit(i, sess->sess_mask); + } spin_unlock(&sess->lock); if (i >= TEE_NUM_SESSIONS) { pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS); + handle_close_session(ta_handle, session_info); handle_unload_ta(ta_handle); kref_put(&sess->refcount, destroy_session); rc = -ENOMEM; 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); - spin_lock(&sess->lock); - clear_bit(i, sess->sess_mask); - spin_unlock(&sess->lock); - handle_unload_ta(ta_handle); - kref_put(&sess->refcount, destroy_session); - goto out; - } - - sess->session_info[i] = session_info; - set_session_id(ta_handle, i, &arg->session); out: free_pages((u64)ta, get_order(ta_size)); return rc;