Commit 30a9d7af authored by Chandan Rajendra's avatar Chandan Rajendra Committed by Theodore Ts'o

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: c9de560dSigned-off-by: default avatarChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
parent 69e43e8c
...@@ -2287,7 +2287,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) ...@@ -2287,7 +2287,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
struct ext4_group_info *grinfo; struct ext4_group_info *grinfo;
struct sg { struct sg {
struct ext4_group_info info; struct ext4_group_info info;
ext4_grpblk_t counters[16]; ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
} sg; } sg;
group--; group--;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment