Kernel panic is observed when network manager is stopped while system
is entering into hibernation. The root cause of the issue is scan work
function keeps running even after cancel_hw_scan() call.
Issue is resolved by calling cancel_work_sync().
Please follow SRU patch submission guidelines to clearly indicate which
series this patch is targeted for, along with correct tags in the patch
subject line. Non compliance leads to critical patches not being
included and missing release deadlines.
See  for guidelines on SRU stable patch format. Canonical has also
shared a document with Redpine  which describes the process clearly.