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From: Dominik Brodowski <linux@dominikbrodowski.net>
To: "Jason A . Donenfeld" <Jason@zx2c4.com>,
	Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org
Subject: [PATCH 0/2] random: fix write locking for crng_init
Date: Sat,  5 Feb 2022 11:34:56 +0100	[thread overview]
Message-ID: <20220205103458.133386-1-linux@dominikbrodowski.net> (raw)

According to a comment in random.c, crng_init is protected by
primary_crng->lock. These two patches fix the locking for
writing tp (that is: increasing) crng_init in call sites where it
may matter. At rand_initialize() time (precisely: either in
crng_initialize_primary() or in crng_finalize_init()), crng_init
is set to 2 without the lock being held. However, then the
kernel is running with IRQs disabled and only the boot CPU
active (but not yet in PID 1).

Dominik Brodowski (2):
  random: fix locking in crng_fast_load()
  random: fix locking for crng_init in crng_reseed()

 drivers/char/random.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

-- 
2.35.1


             reply	other threads:[~2022-02-05 10:35 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-05 10:34 Dominik Brodowski [this message]
2022-02-05 10:34 ` [PATCH 1/2] random: fix locking in crng_fast_load() Dominik Brodowski
2022-02-05 13:17   ` Jason A. Donenfeld
2022-02-05 13:32     ` Dominik Brodowski
2022-02-21  2:32   ` Eric Biggers
2022-02-05 10:34 ` [PATCH 2/2] random: fix locking for crng_init in crng_reseed() Dominik Brodowski

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