From: Chandan Rajendra <chan...@linux.vnet.ibm.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 30a9d7afe70ed6bd9191d3000e2ef1a34fb58493 upstream.
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.
Fixes: c9de560ded61f
Signed-off-by: Chandan Rajendra <chan...@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <ty...@mit.edu>
Reviewed-by: Jan Kara <j...@suse.cz>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
---
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 d775b7b02dd0..2b4ed2bf9569 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2243,7 +2243,7 @@ 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[EXT4_MAX_BLOCK_LOG_SIZE + 2];
} sg;
group--;
--
2.11.0
