[PATCH 0/5] padata: fix liftime issues after ->serial() has completed

[Nicolai Stange]

Hi all,

this series is supposed to fix some lifetime issues all related to the fact that
once the last ->serial() has been invoked, the padata user (i.e. pcrypt) is well
with its right to tear down the associated padata_shell or parallel_data
instance respectively.

Only the first one, addressed by patch [2/5], has actually been observed, namely
on a (downstream) RT kernel under a very specific workload involving LTP's
pcrypt_aead01. On non-RT, I've been unable to reproduce.

The remainder of this series, 3-5/5, fixes two more, somewhat related, but
purely theoretical issues I spotted when scratching my head about possible
reasons for the original Oops.

Thanks!

Nicolai

Nicolai Stange (5):
  padata: introduce internal padata_get/put_pd() helpers
  padata: make padata_free_shell() to respect pd's ->refcnt
  padata: grab parallel_data refcnt for reorder
  padata: split out dequeue operation from padata_find_next()
  padata: avoid potential UAFs to the padata_shell from padata_reorder()

 kernel/padata.c | 129 +++++++++++++++++++++++++++++++++++-------------
 1 file changed, 96 insertions(+), 33 deletions(-)

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2.37.3