tree 9c8c589c6c34e4846d06b2967a5392f32a479831
parent 69e43e8cc971a79dd1ee5d4343d8e63f82725123
author Chandan Rajendra <chandan@linux.vnet.ibm.com> 1479176786 -0500
committer Theodore Ts'o <tytso@mit.edu> 1479176786 -0500

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: c9de560ded61f
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