Re: [PATCH v2] random32: avoid attempt to late reseed if in the middle of seeding

From: Daniel Borkmann
Date: Thu Mar 27 2014 - 04:53:25 EST


On 03/27/2014 07:01 AM, Sasha Levin wrote:
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.

Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>

Looks better now, thanks!

Fixes: 4af712e8df99 ("random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized")
Acked-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
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