3.16.76-rc1 review patch. If anyone has any objections, please let me know.
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From: Eric Biggers ebiggers@google.com
commit 5c6bc4dfa515738149998bb0db2481a4fdead979 upstream.
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 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 Signed-off-by: Ben Hutchings ben@decadent.org.uk --- crypto/ghash-generic.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/crypto/ghash-generic.c +++ b/crypto/ghash-generic.c @@ -45,6 +45,7 @@ static int ghash_setkey(struct crypto_sh 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); @@ -53,7 +54,12 @@ static int ghash_setkey(struct crypto_sh
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;