random32: avoid attempt to late reseed if in the middle of seeding
authorSasha Levin <sasha.levin@oracle.com>
Fri, 28 Mar 2014 16:38:42 +0000 (17:38 +0100)
committerDavid S. Miller <davem@davemloft.net>
Fri, 28 Mar 2014 20:04:19 +0000 (16:04 -0400)
commit05efa8c943b1d5d90fa8c8147571837573338bb6
tree7882312770611805d896178894810f0d9467469b
parent335a67d2ad481b03607bf30a38c28178fa1ad61a
random32: avoid attempt to late reseed if in the middle of seeding

Commit 4af712e8df ("random32: add prandom_reseed_late() and call when
nonblocking pool becomes initialized") has added a late reseed stage
that happens as soon as the nonblocking pool is marked as initialized.

This fails in the case that the nonblocking pool gets initialized
during __prandom_reseed()'s call to get_random_bytes(). In that case
we'd double back into __prandom_reseed() in an attempt to do a late
reseed - deadlocking on 'lock' early on in the boot process.

Instead, just avoid even waiting to do a reseed if a reseed is already
occuring.

Fixes: 4af712e8df99 ("random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
lib/random32.c