smb3: add additional null check in SMB2_ioctl

Although unlikely for it to be possible for rsp to be null here,
the check is safer to add, and quiets a Coverity warning.

Addresses-Coverity: 1443909 ("Explicit Null dereference")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index b20398a..4dda260 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3162,6 +3162,16 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
        if ((plen == NULL) || (out_data == NULL))
                goto ioctl_exit;
 
+       /*
+        * Although unlikely to be possible for rsp to be null and rc not set,
+        * adding check below is slightly safer long term (and quiets Coverity
+        * warning)
+        */
+       if (rsp == NULL) {
+               rc = -EIO;
+               goto ioctl_exit;
+       }
+
        *plen = le32_to_cpu(rsp->OutputCount);
 
        /* We check for obvious errors in the output buffer length and offset */