hpfs: kstrdup() out of memory handling

commit ce657611 upstream.

There is a possibility of nothing being allocated to the new_opts in
case of memory pressure, therefore return ENOMEM for such case.
Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Signed-off-by: Mikulas Patocka <mikulas@twibright.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

fs/hpfs/super.c

@@ -425,6 +425,9 @@ static int hpfs_remount_fs(struct super_block *s, int *flags, char *data)
 	struct hpfs_sb_info *sbi = hpfs_sb(s);
 	char *new_opts = kstrdup(data, GFP_KERNEL);
 
+	if (!new_opts)
+		return -ENOMEM;
+
 	sync_filesystem(s);
 
 	*flags |= MS_NOATIME;