[PATCH 4.2.y-ckt 063/218] quota: Fix possible GPF due to uninitialised pointers

From: Kamal Mostafa
Date: Thu Mar 31 2016 - 17:10:41 EST


4.2.8-ckt7 -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>
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 20d1f74..19c777a 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1393,7 +1393,7 @@ static int dquot_active(const struct inode *inode)
static void __dquot_initialize(struct inode *inode, int type)
{
int cnt, init_needed = 0;
- struct dquot **dquots, *got[MAXQUOTAS];
+ struct dquot **dquots, *got[MAXQUOTAS] = {};
struct super_block *sb = inode->i_sb;
qsize_t rsv;

@@ -1408,7 +1408,6 @@ static void __dquot_initialize(struct inode *inode, int type)
kprojid_t projid;
int rc;

- got[cnt] = NULL;
if (type != -1 && cnt != type)
continue;
/*
--
2.7.4