random: properly align get_random_int_hash

PATCH Applied Eric Biggers 2 participants 2 messages Apr 1, 2016 – May 5, 2016 Random number driver

Share & tools

Eric Biggers

author

2016-04-01 01:12 UTC #0 lore raw

PATCH 1/1 random: properly align get_random_int_hash

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 <[email protected]>

---
 drivers/char/random.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

drivers/char/random.c +3 -1

index b583e53..f867ef4 100644
@@ -1792,13 +1792,15 @@ 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;

Signature · 1 line

2.7.4

Theodore Ts'o

maintainer Applied

2016-05-05 01:08 UTC #1 lore raw

Quoted 5 lines · Eric Biggers

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 <[email protected]>

Thanks, applied.

- Ted