[PATCH 3.16 028/366] crypto: x86/cast5-avx - fix ECB encryption when long sg follows short one

Ben Hutchings
2018-10-14T23:27:58Z

From: Eric Biggers <ebiggers@google.com>

commit 8f461b1e02ed546fbd0f11611138da67fd85a30f upstream.

With ecb-cast5-avx, if a 128+ byte scatterlist element followed a
shorter one, then the algorithm accidentally encrypted/decrypted only 8
bytes instead of the expected 128 bytes. Fix it by setting the
encryption/decryption 'fn' correctly.

Fixes: c12ab20b162c ("crypto: cast5/avx - avoid using temporary stack buffers")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/crypto/cast5_avx_glue.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/arch/x86/crypto/cast5_avx_glue.c
+++ b/arch/x86/crypto/cast5_avx_glue.c
@@ -67,8 +67,6 @@ static int ecb_crypt(struct blkcipher_de
void (*fn)(struct cast5_ctx *ctx, u8 *dst, const u8 *src);
int err;

- fn = (enc) ? cast5_ecb_enc_16way : cast5_ecb_dec_16way;
-
err = blkcipher_walk_virt(desc, walk);
desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

@@ -80,6 +78,7 @@ static int ecb_crypt(struct blkcipher_de

/* Process multi-block batch */
if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
+ fn = (enc) ? cast5_ecb_enc_16way : cast5_ecb_dec_16way;
do {
fn(ctx, wdst, wsrc);