Files
linux/kernel
Daniel Jordan 8e0681dd4e padata: Always leave BHs disabled when running ->parallel()
[ Upstream commit 34c3a47d20 ]

A deadlock can happen when an overloaded system runs ->parallel() in the
context of the current task:

    padata_do_parallel
      ->parallel()
        pcrypt_aead_enc/dec
          padata_do_serial
            spin_lock(&reorder->lock) // BHs still enabled
              <interrupt>
                ...
                  __do_softirq
                    ...
                      padata_do_serial
                        spin_lock(&reorder->lock)

It's a bug for BHs to be on in _do_serial as Steffen points out, so
ensure they're off in the "current task" case like they are in
padata_parallel_worker to avoid this situation.

Reported-by: syzbot+bc05445bc14148d51915@syzkaller.appspotmail.com
Fixes: 4611ce2246 ("padata: allocate work structures for parallel jobs from a pool")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:15:50 +01:00
..
2023-01-04 11:39:23 +01:00
2023-01-04 11:39:23 +01:00
2020-08-12 10:58:02 -07:00
2023-01-14 10:15:20 +01:00
2020-11-14 11:26:04 -08:00
2020-07-27 14:31:12 -04:00