quota: Fix possible GPF due to uninitialised pointers

commit ab73ef46 upstream.

When dqget() in __dquot_initialize() fails e.g. due to IO error,
__dquot_initialize() will pass an array of uninitialized pointers to
dqput_all() and thus can lead to deference of random data. Fix the
problem by properly initializing the array.
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Jan Kara <jack@suse.cz>
[ kamal: backport to 3.13-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

fs/quota/dquot.c

@@ -1403,7 +1403,7 @@ static int dquot_active(const struct inode *inode)
 static void __dquot_initialize(struct inode *inode, int type)
 {
 	int cnt;
-	struct dquot *got[MAXQUOTAS];
+	struct dquot *got[MAXQUOTAS] = {};
 	struct super_block *sb = inode->i_sb;
 	qsize_t rsv;
 
@@ -1415,7 +1415,6 @@ static void __dquot_initialize(struct inode *inode, int type)
 	/* First get references to structures we might need. */
 	for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
 		struct kqid qid;
-		got[cnt] = NULL;
 		if (type != -1 && cnt != type)
 			continue;
 		switch (cnt) {