reiserfs: Fix memory leak in reiserfs_parse_options()

[ Upstream commit e9d4709f ]

When a usrjquota or grpjquota mount option is used multiple times, we
will leak memory allocated for the file name. Make sure the last setting
is used and all the previous ones are properly freed.

Reported-by: syzbot+c9e294bbe0333a6b7640@syzkaller.appspotmail.com
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

fs/reiserfs/super.c

@@ -1264,6 +1264,10 @@ static int reiserfs_parse_options(struct super_block *s,
 						 "turned on.");
 				return 0;
 			}
+			if (qf_names[qtype] !=
+			    REISERFS_SB(s)->s_qf_names[qtype])
+				kfree(qf_names[qtype]);
+			qf_names[qtype] = NULL;
 			if (*arg) {	/* Some filename specified? */
 				if (REISERFS_SB(s)->s_qf_names[qtype]
 				    && strcmp(REISERFS_SB(s)->s_qf_names[qtype],
@@ -1293,10 +1297,6 @@ static int reiserfs_parse_options(struct super_block *s,
 				else
 					*mount_options |= 1 << REISERFS_GRPQUOTA;
 			} else {
-				if (qf_names[qtype] !=
-				    REISERFS_SB(s)->s_qf_names[qtype])
-					kfree(qf_names[qtype]);
-				qf_names[qtype] = NULL;
 				if (qtype == USRQUOTA)
 					*mount_options &= ~(1 << REISERFS_USRQUOTA);
 				else