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random: properly align get_random_int_hash
authorEric Biggers <ebiggers3@gmail.com>
Thu, 5 May 2016 01:08:39 +0000 (21:08 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 14 Jun 2017 11:16:23 +0000 (13:16 +0200)
commit b1132deac01c2332d234fa821a70022796b79182 upstream.

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.

Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/char/random.c

index d93dfeb..1822472 100644 (file)
@@ -1798,13 +1798,15 @@ 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;