[PATCH 5.15.y 2/2] smb: client: fix iface port assignment in parse_server_interfaces

[Sasha Levin <sashal@kernel.org>]

From: Henrique Carvalho <henrique.carvalho@suse.com>

[ Upstream commit d4c7210d2f3ea481a6481f03040a64d9077a6172 ]

parse_server_interfaces() initializes interface socket addresses with
CIFS_PORT. When the mount uses a non-default port this overwrites the
configured destination port.

Later, cifs_chan_update_iface() copies this sockaddr into server->dstaddr,
causing reconnect attempts to use the wrong port after server interface
updates.

Use the existing port from server->dstaddr instead.

Cc: stable@vger.kernel.org
Fixes: fe856be475f7 ("CIFS: parse and store info on iface queries")
Tested-by: Dr. Thomas Orgis <thomas.orgis@uni-hamburg.de>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
[ Different paths, some minor API diffs ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/smb2ops.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 619905fc694e4..bb56cd4e134ae 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -498,6 +498,7 @@ smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 static int
 parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 			size_t buf_len,
+			struct cifs_ses *ses,
 			struct cifs_server_iface **iface_list,
 			size_t *iface_count)
 {
@@ -507,6 +508,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 	struct iface_info_ipv4 *p4;
 	struct iface_info_ipv6 *p6;
 	struct cifs_server_iface *info;
+	__be16 port;
 	ssize_t bytes_left;
 	size_t next = 0;
 	int nb_iface = 0;
@@ -553,6 +555,15 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 		goto out;
 	}
 
+	spin_lock(&cifs_tcp_ses_lock);
+	if (ses->server->dstaddr.ss_family == AF_INET)
+		port = ((struct sockaddr_in *)&ses->server->dstaddr)->sin_port;
+	else if (ses->server->dstaddr.ss_family == AF_INET6)
+		port = ((struct sockaddr_in6 *)&ses->server->dstaddr)->sin6_port;
+	else
+		port = cpu_to_be16(CIFS_PORT);
+	spin_unlock(&cifs_tcp_ses_lock);
+
 	info = *iface_list;
 	bytes_left = buf_len;
 	p = buf;
@@ -579,7 +590,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 			memcpy(&addr4->sin_addr, &p4->IPv4Address, 4);
 
 			/* [MS-SMB2] 2.2.32.5.1.1 Clients MUST ignore these */
-			addr4->sin_port = cpu_to_be16(CIFS_PORT);
+			addr4->sin_port = port;
 
 			cifs_dbg(FYI, "%s: ipv4 %pI4\n", __func__,
 				 &addr4->sin_addr);
@@ -593,7 +604,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 			/* [MS-SMB2] 2.2.32.5.1.2 Clients MUST ignore these */
 			addr6->sin6_flowinfo = 0;
 			addr6->sin6_scope_id = 0;
-			addr6->sin6_port = cpu_to_be16(CIFS_PORT);
+			addr6->sin6_port = port;
 
 			cifs_dbg(FYI, "%s: ipv6 %pI6\n", __func__,
 				 &addr6->sin6_addr);
@@ -660,7 +671,7 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon)
 		goto out;
 	}
 
-	rc = parse_server_interfaces(out_buf, ret_data_len,
+	rc = parse_server_interfaces(out_buf, ret_data_len, ses,
 				     &iface_list, &iface_count);
 	if (rc)
 		goto out;
-- 
2.51.0