From ce465bf94b70f03136171a62b607864f00093b19 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Thu, 11 Jul 2019 13:46:58 +1000 Subject: [PATCH] cifs: fix crash in cifs_dfs_do_automount RHBZ: 1649907 Fix a crash that happens while attempting to mount a DFS referral from the same server on the root of a filesystem. Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French --- fs/cifs/connect.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 8ad8bbe8003b..6331c4f93b59 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -4484,11 +4484,13 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, - char *full_path) + char *full_path, + int added_treename) { int rc; char *s; char sep, tmp; + int skip = added_treename ? 1 : 0; sep = CIFS_DIR_SEP(cifs_sb); s = full_path; @@ -4503,7 +4505,14 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, /* next separator */ while (*s && *s != sep) s++; - + /* + * if the treename is added, we then have to skip the first + * part within the separators + */ + if (skip) { + skip = 0; + continue; + } /* * temporarily null-terminate the path at the end of * the current component @@ -4551,8 +4560,7 @@ static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol, if (rc != -EREMOTE) { rc = cifs_are_all_path_components_accessible(server, xid, tcon, - cifs_sb, - full_path); + cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS); if (rc != 0) { cifs_dbg(VFS, "cannot query dirs between root and final path, " "enabling CIFS_MOUNT_USE_PREFIX_PATH\n");