Commits
Mikulas Patocka committed b06075a98d5
dm: fix use after free crash due to incorrect cleanup sequence
Linux 4.2-rc1 Commit 0f20972f7bf6 ("dm: factor out a common
cleanup_mapped_device()") moved a common cleanup code to a separate
function. Unfortunately, that commit incorrectly changed the order of
cleanup, so that it destroys the mapped_device's srcu structure
'io_barrier' before destroying its workqueue.
The function that is executed on the workqueue (dm_wq_work) uses the srcu
structure, thus it may use it after being freed. That results in a
crash in the LVM test suite's mirror-vgreduce-removemissing.sh test.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 0f20972f7bf6 ("dm: factor out a common cleanup_mapped_device()")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>