On Thu, May 30, 2019 at 6:51 PM Eric Biggers ebiggers@kernel.org wrote:
From: Eric Biggers ebiggers@google.com
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
Tested-by: Peter Robinson pbrobinson@gmail.com
That fixes the problems I was seeing, thanks for the quick response/fix.
Peter
Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers ebiggers@google.com
crypto/ghash-generic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/crypto/ghash-generic.c b/crypto/ghash-generic.c index e6307935413c1..c8a347798eae6 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) gf128mul_free_4k(ctx->gf128);
ctx->gf128 = gf128mul_init_4k_lle((be128 *)key);
BUILD_BUG_ON(sizeof(k) != GHASH_BLOCK_SIZE);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;-- 2.22.0.rc1.257.g3120a18244-goog