Merge tag '4.18-fixes-smb3' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:

 - one smb3 (ACL related) fix for stable

 - one SMB3 security enhancement (when mounting -t smb3 forbid less
   secure dialects)

 - some RDMA and compounding fixes

* tag '4.18-fixes-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix a buffer leak in smb2_query_symlink
  smb3: do not allow insecure cifs mounts when using smb3
  CIFS: Fix NULL ptr deref
  CIFS: fix encryption in SMB3.1.1
  CIFS: Pass page offset for encrypting
  CIFS: Pass page offset for calculating signature
  CIFS: SMBD: Support page offset in memory registration
  CIFS: SMBD: Support page offset in RDMA recv
  CIFS: SMBD: Support page offset in RDMA send
  CIFS: When sending data on socket, pass the correct page offset
  CIFS: Introduce helper function to get page offset and length in smb_rqst
  CIFS: Calculate the correct request length based on page offset and tail size
  cifs: For SMB2 security informaion query, check for minimum sized security descriptor instead of sizeof FileAllInformation class
  CIFS: Fix signing for SMB2/3

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index cb5728e3d87d..e2bec47c6845 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -453,8 +453,10 @@ cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
 		start_of_path = from + 1;
 #ifdef CONFIG_CIFS_SMB311
 	/* SMB311 POSIX extensions paths do not include leading slash */
-	else if (cifs_sb_master_tcon(cifs_sb)->posix_extensions)
+	else if (cifs_sb_master_tlink(cifs_sb) &&
+		 cifs_sb_master_tcon(cifs_sb)->posix_extensions) {
 		start_of_path = from + 1;
+	}
 #endif /* 311 */
 	else
 		start_of_path = from;