[PATCH 3.13.y-ckt 26/97] quota: Fix possible GPF due to uninitialised pointers

From: Kamal Mostafa
Date: Mon Apr 04 2016 - 19:28:07 EST


3.13.11-ckt38 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Nikolay Borisov <kernel@xxxxxxxx>

commit ab73ef46398e2c0159f3a71de834586422d2a44a 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@xxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
[ kamal: backport to 3.13-stable: context ]
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
fs/quota/dquot.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 064e9eb..995b90f 100644
--- a/fs/quota/dquot.c
+++ b/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) {
--
2.7.4