commit 1e1132ea21da6d7be92a72195204379c819cb70b
author Mikulas Patocka <mpatocka@redhat.com> Thu Aug 16 12:23:19 2018 -0400
committer Mike Snitzer <snitzer@redhat.com> Thu Aug 16 13:43:01 2018 -0400
tree b983945975d697c37ac0193d18ca022cca4c3fb0
parent bc9e9cf0401f18e33b78d4c8a518661b8346baf7

dm writecache: fix a crash due to reading past end of dirty_bitmap

wc->dirty_bitmap_size is in bytes so must multiply it by 8, not by
BITS_PER_LONG, to get number of bitmap_bits.

Fixes crash in find_next_bit() that was reported:
https://bugzilla.kernel.org/show_bug.cgi?id=200819

Reported-by: edo.rus@gmail.com
Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>