From: Chandan Rajendra <chandan@linux.vnet.ibm.com>
To: linux-ext4@vger.kernel.org
Cc: Chandan Rajendra <chandan@linux.vnet.ibm.com>,
tytso@mit.edu, jack@suse.cz, adilger@dilger.ca
Subject: [PATCH] ext4: ext4_mb_seq_groups_show: Fix stack memory corruption
Date: Mon, 7 Nov 2016 12:15:41 +0530 [thread overview]
Message-ID: <1478501141-15651-1-git-send-email-chandan@linux.vnet.ibm.com> (raw)
The number of 'counters' elements needed in 'struct sg' is
super_block->s_blocksize_bits + 2. Presently we have 16 'counters'
elements in the array. This is insufficient for block sizes >= 32k. In
such cases the memcpy operation performed in ext4_mb_seq_groups_show()
would cause stack memory corruption.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
fs/ext4/mballoc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index a937ac7..67e6fcb 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2287,7 +2287,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
struct ext4_group_info *grinfo;
struct sg {
struct ext4_group_info info;
- ext4_grpblk_t counters[16];
+ ext4_grpblk_t counters[16 + 2];
} sg;
group--;
--
2.5.5
next reply other threads:[~2016-11-07 6:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-07 6:45 Chandan Rajendra [this message]
2016-11-08 9:21 ` [PATCH] ext4: ext4_mb_seq_groups_show: Fix stack memory corruption Jan Kara
2016-11-10 5:44 ` Chandan Rajendra
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