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From: "Theodore Ts'o" <tytso@mit.edu>
To: Linux Kernel Developers List <linux-kernel@vger.kernel.org>
Cc: linux-crypto@vger.kernel.org, smueller@chronox.de,
	herbert@gondor.apana.org.au, andi@firstfloor.org,
	sandyinchina@gmail.com, jsd@av8n.com, hpa@zytor.com,
	Eric Biggers <ebiggers3@gmail.com>,
	stable@kernel.org, "Theodore Ts'o" <tytso@mit.edu>
Subject: [PATCH 4/7] random: properly align get_random_int_hash
Date: Mon, 13 Jun 2016 11:48:36 -0400	[thread overview]
Message-ID: <1465832919-11316-5-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <1465832919-11316-1-git-send-email-tytso@mit.edu>

From: Eric Biggers <ebiggers3@gmail.com>

get_random_long() reads from the get_random_int_hash array using an
unsigned long pointer.  For this code to be guaranteed correct on all
architectures, the array must be aligned to an unsigned long boundary.

Cc: stable@kernel.org
Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 drivers/char/random.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 64e35a4..83f5cd0 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1778,13 +1778,15 @@ int random_int_secret_init(void)
 	return 0;
 }
 
+static DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash)
+		__aligned(sizeof(unsigned long));
+
 /*
  * Get a random word for internal kernel use only. Similar to urandom but
  * with the goal of minimal entropy pool depletion. As a result, the random
  * value is not cryptographically secure but for several uses the cost of
  * depleting entropy is too high
  */
-static DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash);
 unsigned int get_random_int(void)
 {
 	__u32 *hash;
-- 
2.5.0

  parent reply	other threads:[~2016-06-13 15:51 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-13 15:48 [PATCH-v4 0/7] random: replace urandom pool with a CRNG Theodore Ts'o
2016-06-13 15:48 ` [PATCH 1/7] random: initialize the non-blocking pool via add_hwgenerator_randomness() Theodore Ts'o
2016-06-13 15:48 ` [PATCH 2/7] random: print a warning for the first ten uninitialized random users Theodore Ts'o
2016-06-13 15:48 ` [PATCH 3/7] random: add interrupt callback to VMBus IRQ handler Theodore Ts'o
2016-06-13 15:48 ` Theodore Ts'o [this message]
2016-06-13 15:48 ` [PATCH 5/7] random: replace non-blocking pool with a Chacha20-based CRNG Theodore Ts'o
2016-06-13 18:00   ` Stephan Mueller
2016-06-13 19:03     ` Theodore Ts'o
2016-06-15 14:59   ` Herbert Xu
2016-06-19 23:18     ` Theodore Ts'o
2016-06-20  1:25       ` Herbert Xu
2016-06-20  5:02         ` Theodore Ts'o
2016-06-20  5:19           ` Herbert Xu
2016-06-20 15:01             ` Theodore Ts'o
2016-06-20 15:49               ` Stephan Mueller
2016-06-20 18:52                 ` H. Peter Anvin
2016-06-20 23:48                 ` Theodore Ts'o
2016-06-26 18:47       ` Pavel Machek
2016-06-26 19:10         ` Stephan Mueller
2016-06-26 22:51         ` Theodore Ts'o
2016-06-13 15:48 ` [PATCH 6/7] random: make /dev/urandom scalable for silly userspace programs Theodore Ts'o
2016-08-21  9:53   ` Jan Varho
2016-08-21 11:36     ` Theodore Ts'o
2016-06-13 15:48 ` [PATCH 7/7] random: add backtracking protection to the CRNG Theodore Ts'o
2016-06-26 18:47   ` Pavel Machek
2016-06-26 23:05     ` Theodore Ts'o

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