cifs: add NULL check for ses->tcon_ipc

In some scenarios (DFS and BAD_NETWORK_NAME) set_root_set() can be
called with a NULL ses->tcon_ipc.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 28c1459fb0fc06d78cf56a02e27898dc3d294a6c..44f9cce57099583cba0e2ef99bcfb963f88b91f1 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -4546,7 +4546,8 @@ static void set_root_ses(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
        if (ses) {
                spin_lock(&cifs_tcp_ses_lock);
                ses->ses_count++;
-               ses->tcon_ipc->remap = cifs_remap(cifs_sb);
+               if (ses->tcon_ipc)
+                       ses->tcon_ipc->remap = cifs_remap(cifs_sb);
                spin_unlock(&cifs_tcp_ses_lock);
        }
        *root_ses = ses;