path: root/crypto/ghash-generic.c
diff options
authorEric Biggers <ebiggers@google.com>2019-05-30 10:50:39 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2019-06-06 14:38:57 +0800
commit5c6bc4dfa515738149998bb0db2481a4fdead979 (patch)
tree4e5e9129c4eb8fcc6dc9329ccaaa9dd6a7f6dd58 /crypto/ghash-generic.c
parent67882e76492483bafa9b1b1648bb031e9abe5185 (diff)
crypto: ghash - fix unaligned memory access in ghash_setkey()
Changing ghash_mod_init() to be subsys_initcall made it start running before the alignment fault handler has been installed on ARM. In kernel builds where the keys in the ghash test vectors happened to be misaligned in the kernel image, this exposed the longstanding bug that ghash_setkey() is incorrectly casting the key buffer (which can have any alignment) to be128 for passing to gf128mul_init_4k_lle(). Fix this by memcpy()ing the key to a temporary buffer. Don't fix it by setting an alignmask on the algorithm instead because that would unnecessarily force alignment of the data too. Fixes: 2cdc6899a88e ("crypto: ghash - Add GHASH digest algorithm for GCM") Reported-by: Peter Robinson <pbrobinson@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Tested-by: Peter Robinson <pbrobinson@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/ghash-generic.c')
1 files changed, 7 insertions, 1 deletions
diff --git a/crypto/ghash-generic.c b/crypto/ghash-generic.c
index e6307935413c..c8a347798eae 100644
--- a/crypto/ghash-generic.c
+++ b/crypto/ghash-generic.c
@@ -34,6 +34,7 @@ static int ghash_setkey(struct crypto_shash *tfm,
const u8 *key, unsigned int keylen)
struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
+ be128 k;
if (keylen != GHASH_BLOCK_SIZE) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
@@ -42,7 +43,12 @@ static int ghash_setkey(struct crypto_shash *tfm,
if (ctx->gf128)
- ctx->gf128 = gf128mul_init_4k_lle((be128 *)key);
+ memcpy(&k, key, GHASH_BLOCK_SIZE); /* avoid violating alignment rules */
+ ctx->gf128 = gf128mul_init_4k_lle(&k);
+ memzero_explicit(&k, GHASH_BLOCK_SIZE);
if (!ctx->gf128)
return -ENOMEM;