From: Tudor Ambarus tudor.ambarus@microchip.com
commit 86ef1dfcb561473fbf5e199d58d18c55554d78be upstream.
commit 394a9e044702 ("crypto: cfb - add missing 'chunksize' property") adds a test vector where the input length is smaller than the IV length (the second test vector). This revealed a NULL pointer dereference in the atmel-aes driver, that is caused by passing an incorrect offset in scatterwalk_map_and_copy() when atmel_aes_complete() is called.
Do not save the IV in req->info of ablkcipher_request (or equivalently req->iv of skcipher_request) when req->nbytes < ivsize, because the IV will not be further used.
While touching the code, modify the type of ivsize from int to unsigned int, to comply with the return type of crypto_ablkcipher_ivsize().
Fixes: 91308019ecb4 ("crypto: atmel-aes - properly set IV after {en,de}crypt") Cc: stable@vger.kernel.org Signed-off-by: Tudor Ambarus tudor.ambarus@microchip.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/crypto/atmel-aes.c | 53 +++++++++++++++++++++++++-------------------- 1 file changed, 30 insertions(+), 23 deletions(-)
--- a/drivers/crypto/atmel-aes.c +++ b/drivers/crypto/atmel-aes.c @@ -493,6 +493,29 @@ static inline bool atmel_aes_is_encrypt( static void atmel_aes_authenc_complete(struct atmel_aes_dev *dd, int err); #endif
+static void atmel_aes_set_iv_as_last_ciphertext_block(struct atmel_aes_dev *dd) +{ + struct ablkcipher_request *req = ablkcipher_request_cast(dd->areq); + struct atmel_aes_reqctx *rctx = ablkcipher_request_ctx(req); + struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req); + unsigned int ivsize = crypto_ablkcipher_ivsize(ablkcipher); + + if (req->nbytes < ivsize) + return; + + if (rctx->mode & AES_FLAGS_ENCRYPT) { + scatterwalk_map_and_copy(req->info, req->dst, + req->nbytes - ivsize, ivsize, 0); + } else { + if (req->src == req->dst) + memcpy(req->info, rctx->lastc, ivsize); + else + scatterwalk_map_and_copy(req->info, req->src, + req->nbytes - ivsize, + ivsize, 0); + } +} + static inline int atmel_aes_complete(struct atmel_aes_dev *dd, int err) { #ifdef CONFIG_CRYPTO_DEV_ATMEL_AUTHENC @@ -503,26 +526,8 @@ static inline int atmel_aes_complete(str clk_disable(dd->iclk); dd->flags &= ~AES_FLAGS_BUSY;
- if (!dd->ctx->is_aead) { - struct ablkcipher_request *req = - ablkcipher_request_cast(dd->areq); - struct atmel_aes_reqctx *rctx = ablkcipher_request_ctx(req); - struct crypto_ablkcipher *ablkcipher = - crypto_ablkcipher_reqtfm(req); - int ivsize = crypto_ablkcipher_ivsize(ablkcipher); - - if (rctx->mode & AES_FLAGS_ENCRYPT) { - scatterwalk_map_and_copy(req->info, req->dst, - req->nbytes - ivsize, ivsize, 0); - } else { - if (req->src == req->dst) { - memcpy(req->info, rctx->lastc, ivsize); - } else { - scatterwalk_map_and_copy(req->info, req->src, - req->nbytes - ivsize, ivsize, 0); - } - } - } + if (!dd->ctx->is_aead) + atmel_aes_set_iv_as_last_ciphertext_block(dd);
if (dd->is_async) dd->areq->complete(dd->areq, err); @@ -1128,10 +1133,12 @@ static int atmel_aes_crypt(struct ablkci rctx->mode = mode;
if (!(mode & AES_FLAGS_ENCRYPT) && (req->src == req->dst)) { - int ivsize = crypto_ablkcipher_ivsize(ablkcipher); + unsigned int ivsize = crypto_ablkcipher_ivsize(ablkcipher);
- scatterwalk_map_and_copy(rctx->lastc, req->src, - (req->nbytes - ivsize), ivsize, 0); + if (req->nbytes >= ivsize) + scatterwalk_map_and_copy(rctx->lastc, req->src, + req->nbytes - ivsize, + ivsize, 0); }
return atmel_aes_handle_queue(dd, &req->base);