ext4: fix stack memory corruption with 64k block size

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: c9de560ded
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
This commit is contained in:
Chandan Rajendra 2016-11-14 21:26:26 -05:00 committed by Theodore Ts'o
parent 69e43e8cc9
commit 30a9d7afe7
1 changed files with 1 additions and 1 deletions

View File

@ -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[EXT4_MAX_BLOCK_LOG_SIZE + 2];
} sg;
group--;