[PATCH AUTOSEL 6.1 12/47] ksmbd: fix out of bounds in init_smb2_rsp_hdr()

[Sasha Levin <sashal@xxxxxxxxxx>]

From: Namjae Jeon <linkinjeon@xxxxxxxxxx>

[ Upstream commit 536bb492d39bb6c080c92f31e8a55fe9934f452b ]

If client send smb2 negotiate request and then send smb1 negotiate
request, init_smb2_rsp_hdr is called for smb1 negotiate request since
need_neg is set to false. This patch ignore smb1 packets after ->need_neg
is set to false.

Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-21541
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/smb/server/server.c     |  7 ++++++-
 fs/smb/server/smb_common.c | 19 +++++++++++--------
 fs/smb/server/smb_common.h |  2 +-
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c
index 847ee62afb8a1..9804cabe72a84 100644
--- a/fs/smb/server/server.c
+++ b/fs/smb/server/server.c
@@ -286,6 +286,7 @@ static void handle_ksmbd_work(struct work_struct *wk)
 static int queue_ksmbd_work(struct ksmbd_conn *conn)
 {
 	struct ksmbd_work *work;
+	int err;
 
 	work = ksmbd_alloc_work_struct();
 	if (!work) {
@@ -297,7 +298,11 @@ static int queue_ksmbd_work(struct ksmbd_conn *conn)
 	work->request_buf = conn->request_buf;
 	conn->request_buf = NULL;
 
-	ksmbd_init_smb_server(work);
+	err = ksmbd_init_smb_server(work);
+	if (err) {
+		ksmbd_free_work_struct(work);
+		return 0;
+	}
 
 	ksmbd_conn_enqueue_request(work);
 	atomic_inc(&conn->r_count);
diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c
index d937e2f45c829..a4421d9458d90 100644
--- a/fs/smb/server/smb_common.c
+++ b/fs/smb/server/smb_common.c
@@ -388,26 +388,29 @@ static struct smb_version_cmds smb1_server_cmds[1] = {
 	[SMB_COM_NEGOTIATE_EX]	= { .proc = smb1_negotiate, },
 };
 
-static void init_smb1_server(struct ksmbd_conn *conn)
+static int init_smb1_server(struct ksmbd_conn *conn)
 {
 	conn->ops = &smb1_server_ops;
 	conn->cmds = smb1_server_cmds;
 	conn->max_cmds = ARRAY_SIZE(smb1_server_cmds);
+	return 0;
 }
 
-void ksmbd_init_smb_server(struct ksmbd_work *work)
+int ksmbd_init_smb_server(struct ksmbd_work *work)
 {
 	struct ksmbd_conn *conn = work->conn;
 	__le32 proto;
 
-	if (conn->need_neg == false)
-		return;
-
 	proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol;
+	if (conn->need_neg == false) {
+		if (proto == SMB1_PROTO_NUMBER)
+			return -EINVAL;
+		return 0;
+	}
+
 	if (proto == SMB1_PROTO_NUMBER)
-		init_smb1_server(conn);
-	else
-		init_smb3_11_server(conn);
+		return init_smb1_server(conn);
+	return init_smb3_11_server(conn);
 }
 
 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
diff --git a/fs/smb/server/smb_common.h b/fs/smb/server/smb_common.h
index e63d2a4f466b5..1cbb492cdefec 100644
--- a/fs/smb/server/smb_common.h
+++ b/fs/smb/server/smb_common.h
@@ -427,7 +427,7 @@ bool ksmbd_smb_request(struct ksmbd_conn *conn);
 
 int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count);
 
-void ksmbd_init_smb_server(struct ksmbd_work *work);
+int ksmbd_init_smb_server(struct ksmbd_work *work);
 
 struct ksmbd_kstat;
 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work,
-- 
2.40.1