[CIFS] Return better error when server requires signing but client forbids

Signed-off-by: Steve French <sfrench@us.ibm.com>

2 files changed, 5 insertions, 2 deletions

diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 2459ef0a1396..3d419163c3d3 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -11,7 +11,8 @@ connect fails (e.g. due to signing negotiation failure) fix
 leak that causes cifsd not to stop and rmmod to fail to cleanup
 cifs_request_buffers pool. Fix problem with POSIX Open/Mkdir on
 bigendian architectures. Fix possible memory corruption when
-EAGAIN returned on kern_recvmsg.
+EAGAIN returned on kern_recvmsg. Return better error if server
+requires packet signing but client has disabled it.
 
 Version 1.50
 ------------
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index d22af63e8f1f..2b2d4fec3656 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -663,10 +663,12 @@ signing_check:
                 /* MUST_SIGN already includes the MAY_SIGN FLAG
                    so if this is zero it means that signing is disabled */
                 cFYI(1, ("Signing disabled"));
-                if (server->secMode & SECMODE_SIGN_REQUIRED)
+                if (server->secMode & SECMODE_SIGN_REQUIRED) {
                         cERROR(1, ("Server requires "
                                    "packet signing to be enabled in "
                                    "/proc/fs/cifs/SecurityFlags."));
+                        rc = -EOPNOTSUPP;
+                }
                 server->secMode &=
                         ~(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED);
         } else if ((secFlags & CIFSSEC_MUST_SIGN) == CIFSSEC_MUST_SIGN) {