FAILED: patch "[PATCH] ksmbd: validate session id and tree id in the compound" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 5005bcb4219156f1bf7587b185080ec1da08518e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023062114-jet-underwire-9543@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5005bcb4219156f1bf7587b185080ec1da08518e Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@kernel.org>
Date: Thu, 15 Jun 2023 22:05:29 +0900
Subject: [PATCH] ksmbd: validate session id and tree id in the compound
 request

This patch validate session id and tree id in compound request.
If first operation in the compound is SMB2 ECHO request, ksmbd bypass
session and tree validation. So work->sess and work->tcon could be NULL.
If secound request in the compound access work->sess or tcon, It cause
NULL pointer dereferecing error.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21165
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c
index f9b2e0f19b03..ced7a9e916f0 100644
--- a/fs/smb/server/server.c
+++ b/fs/smb/server/server.c
@@ -185,24 +185,31 @@ static void __handle_ksmbd_work(struct ksmbd_work *work,
 		goto send;
 	}
 
-	if (conn->ops->check_user_session) {
-		rc = conn->ops->check_user_session(work);
-		if (rc < 0) {
-			command = conn->ops->get_cmd_val(work);
-			conn->ops->set_rsp_status(work,
-					STATUS_USER_SESSION_DELETED);
-			goto send;
-		} else if (rc > 0) {
-			rc = conn->ops->get_ksmbd_tcon(work);
+	do {
+		if (conn->ops->check_user_session) {
+			rc = conn->ops->check_user_session(work);
 			if (rc < 0) {
-				conn->ops->set_rsp_status(work,
-					STATUS_NETWORK_NAME_DELETED);
+				if (rc == -EINVAL)
+					conn->ops->set_rsp_status(work,
+						STATUS_INVALID_PARAMETER);
+				else
+					conn->ops->set_rsp_status(work,
+						STATUS_USER_SESSION_DELETED);
 				goto send;
+			} else if (rc > 0) {
+				rc = conn->ops->get_ksmbd_tcon(work);
+				if (rc < 0) {
+					if (rc == -EINVAL)
+						conn->ops->set_rsp_status(work,
+							STATUS_INVALID_PARAMETER);
+					else
+						conn->ops->set_rsp_status(work,
+							STATUS_NETWORK_NAME_DELETED);
+					goto send;
+				}
 			}
 		}
-	}
 
-	do {
 		rc = __process_request(work, conn, &command);
 		if (rc == SERVER_HANDLER_ABORT)
 			break;
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index ccecdb71d2bc..da1787c68ba0 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -91,7 +91,6 @@ int smb2_get_ksmbd_tcon(struct ksmbd_work *work)
 	unsigned int cmd = le16_to_cpu(req_hdr->Command);
 	int tree_id;
 
-	work->tcon = NULL;
 	if (cmd == SMB2_TREE_CONNECT_HE ||
 	    cmd ==  SMB2_CANCEL_HE ||
 	    cmd ==  SMB2_LOGOFF_HE) {
@@ -105,10 +104,28 @@ int smb2_get_ksmbd_tcon(struct ksmbd_work *work)
 	}
 
 	tree_id = le32_to_cpu(req_hdr->Id.SyncId.TreeId);
+
+	/*
+	 * If request is not the first in Compound request,
+	 * Just validate tree id in header with work->tcon->id.
+	 */
+	if (work->next_smb2_rcv_hdr_off) {
+		if (!work->tcon) {
+			pr_err("The first operation in the compound does not have tcon\n");
+			return -EINVAL;
+		}
+		if (work->tcon->id != tree_id) {
+			pr_err("tree id(%u) is different with id(%u) in first operation\n",
+					tree_id, work->tcon->id);
+			return -EINVAL;
+		}
+		return 1;
+	}
+
 	work->tcon = ksmbd_tree_conn_lookup(work->sess, tree_id);
 	if (!work->tcon) {
 		pr_err("Invalid tid %d\n", tree_id);
-		return -EINVAL;
+		return -ENOENT;
 	}
 
 	return 1;
@@ -547,7 +564,6 @@ int smb2_check_user_session(struct ksmbd_work *work)
 	unsigned int cmd = conn->ops->get_cmd_val(work);
 	unsigned long long sess_id;
 
-	work->sess = NULL;
 	/*
 	 * SMB2_ECHO, SMB2_NEGOTIATE, SMB2_SESSION_SETUP command do not
 	 * require a session id, so no need to validate user session's for
@@ -558,15 +574,33 @@ int smb2_check_user_session(struct ksmbd_work *work)
 		return 0;
 
 	if (!ksmbd_conn_good(conn))
-		return -EINVAL;
+		return -EIO;
 
 	sess_id = le64_to_cpu(req_hdr->SessionId);
+
+	/*
+	 * If request is not the first in Compound request,
+	 * Just validate session id in header with work->sess->id.
+	 */
+	if (work->next_smb2_rcv_hdr_off) {
+		if (!work->sess) {
+			pr_err("The first operation in the compound does not have sess\n");
+			return -EINVAL;
+		}
+		if (work->sess->id != sess_id) {
+			pr_err("session id(%llu) is different with the first operation(%lld)\n",
+					sess_id, work->sess->id);
+			return -EINVAL;
+		}
+		return 1;
+	}
+
 	/* Check for validity of user session */
 	work->sess = ksmbd_session_lookup_all(conn, sess_id);
 	if (work->sess)
 		return 1;
 	ksmbd_debug(SMB, "Invalid user session, Uid %llu\n", sess_id);
-	return -EINVAL;
+	return -ENOENT;
 }
 
 static void destroy_previous_session(struct ksmbd_conn *conn,