The client was sending rfc1002 session request packet with a wrong
length field set, therefore failing to mount shares against old SMB
servers over port 139.
Fix this by calculating the correct length as specified in rfc1002.
Fixes: d7173623bf0b ("cifs: use ALIGN() and round_up() macros")
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
---
fs/cifs/connect.c | 100 ++++++++++++++++++----------------------------
1 file changed, 38 insertions(+), 62 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index b2a04b4e89a5..af49ae53aaf4 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2843,72 +2843,48 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
* negprot - BB check reconnection in case where second
* sessinit is sent but no second negprot
*/
- struct rfc1002_session_packet *ses_init_buf;
- unsigned int req_noscope_len;
- struct smb_hdr *smb_buf;
+ struct rfc1002_session_packet req = {};
+ struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
+ unsigned int len;
+
+ req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
+
+ if (server->server_RFC1001_name[0] != 0)
+ rfc1002mangle(req.trailer.session_req.called_name,
+ server->server_RFC1001_name,
+ RFC1001_NAME_LEN_WITH_NULL);
+ else
+ rfc1002mangle(req.trailer.session_req.called_name,
+ DEFAULT_CIFS_CALLED_NAME,
+ RFC1001_NAME_LEN_WITH_NULL);
+
+ req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
+
+ /* calling name ends in null (byte 16) from old smb convention */
+ if (server->workstation_RFC1001_name[0] != 0)
+ rfc1002mangle(req.trailer.session_req.calling_name,
+ server->workstation_RFC1001_name,
+ RFC1001_NAME_LEN_WITH_NULL);
+ else
+ rfc1002mangle(req.trailer.session_req.calling_name,
+ "LINUX_CIFS_CLNT",
+ RFC1001_NAME_LEN_WITH_NULL);
- ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
- GFP_KERNEL);
-
- if (ses_init_buf) {
- ses_init_buf->trailer.session_req.called_len = 32;
-
- if (server->server_RFC1001_name[0] != 0)
- rfc1002mangle(ses_init_buf->trailer.
- session_req.called_name,
- server->server_RFC1001_name,
- RFC1001_NAME_LEN_WITH_NULL);
- else
- rfc1002mangle(ses_init_buf->trailer.
- session_req.called_name,
- DEFAULT_CIFS_CALLED_NAME,
- RFC1001_NAME_LEN_WITH_NULL);
-
- ses_init_buf->trailer.session_req.calling_len = 32;
-
- /*
- * calling name ends in null (byte 16) from old smb
- * convention.
- */
- if (server->workstation_RFC1001_name[0] != 0)
- rfc1002mangle(ses_init_buf->trailer.
- session_req.calling_name,
- server->workstation_RFC1001_name,
- RFC1001_NAME_LEN_WITH_NULL);
- else
- rfc1002mangle(ses_init_buf->trailer.
- session_req.calling_name,
- "LINUX_CIFS_CLNT",
- RFC1001_NAME_LEN_WITH_NULL);
-
- ses_init_buf->trailer.session_req.scope1 = 0;
- ses_init_buf->trailer.session_req.scope2 = 0;
- smb_buf = (struct smb_hdr *)ses_init_buf;
-
- /* sizeof RFC1002_SESSION_REQUEST with no scopes */
- req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
+ /*
+ * As per rfc1002, @len must be the number of bytes that follows the
+ * length field of a rfc1002 session request payload.
+ */
+ len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
- /* == cpu_to_be32(0x81000044) */
- smb_buf->smb_buf_length =
- cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
- rc = smb_send(server, smb_buf, 0x44);
- kfree(ses_init_buf);
- /*
- * RFC1001 layer in at least one server
- * requires very short break before negprot
- * presumably because not expecting negprot
- * to follow so fast. This is a simple
- * solution that works without
- * complicating the code and causes no
- * significant slowing down on mount
- * for everyone else
- */
- usleep_range(1000, 2000);
- }
+ smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
+ rc = smb_send(server, smb_buf, len);
/*
- * else the negprot may still work without this
- * even though malloc failed
+ * RFC1001 layer in at least one server requires very short break before
+ * negprot presumably because not expecting negprot to follow so fast.
+ * This is a simple solution that works without complicating the code
+ * and causes no significant slowing down on mount for everyone else
*/
+ usleep_range(1000, 2000);
return rc;
}
--
2.39.1
