[PATCH 5.5 011/119] cifs: fix potential mismatch of UNC paths

[Greg Kroah-Hartman]

From: Paulo Alcantara (SUSE) <pc@xxxxxx>

[ Upstream commit 154255233830e1e4dd0d99ac929a5dce588c0b81 ]

Ensure that full_path is an UNC path that contains '\\' as delimiter,
which is required by cifs_build_devname().

The build_path_from_dentry_optional_prefix() function may return a
path with '/' as delimiter when using SMB1 UNIX extensions, for
example.

Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Acked-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/cifs/cifs_dfs_ref.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index 606f26d862dc1..cc3ada12848d9 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -324,6 +324,8 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
 	if (full_path == NULL)
 		goto cdda_exit;
 
+	convert_delimiter(full_path, '\\');
+
 	cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
 
 	if (!cifs_sb_master_tlink(cifs_sb)) {
-- 
2.20.1