SMB3: Fix deadlock in validate negotiate hits reconnect

Currently we skip SMB2_TREE_CONNECT command when checking during
reconnect because Tree Connect happens when establishing
an SMB session. For SMB 3.0 protocol version the code also calls
validate negotiate which results in SMB2_IOCL command being sent
over the wire. This may deadlock on trying to acquire a mutex when
checking for reconnect. Fix this by skipping SMB2_IOCL command
when doing the reconnect check.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index c8cd7b6cdda2a5c93b0c6a5cf374d6b29291726e..33efc5fb293c8b4625bcf427d751f86ca3611f03 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -252,7 +252,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
        if (tcon == NULL)
                return 0;
 
-       if (smb2_command == SMB2_TREE_CONNECT)
+       if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL)
                return 0;
 
        if (tcon->tidStatus == CifsExiting) {