From dfb098d692eac2a11a7051dfe87be98cd90da67d Mon Sep 17 00:00:00 2001 From: Corentin Labbe Date: Wed, 5 May 2021 20:26:10 +0000 Subject: [PATCH] crypto: ixp4xx - fallback when having more than one SG Testing ixp4xx_crypto lead to: alg: skcipher: ecb(des)-ixp4xx encryption overran dst buffer on test vector 0, cfg="two even aligned splits" The HW overwrites destination always when sg_nents() > 1. The problem seems that the HW always write areq->cryptlen bytes on the last SG. A comment in driver's code seems to give a clue that multiple SG was not planned "This was never tested by Intel for more than one dst buffer, I think". So let's add a fallback for this situation. Signed-off-by: Corentin Labbe Signed-off-by: Herbert Xu --- drivers/crypto/Kconfig | 5 ++++ drivers/crypto/ixp4xx_crypto.c | 56 +++++++++++++++++++++++++++++++++++++++--- 2 files changed, 58 insertions(+), 3 deletions(-) diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig index 1fe5b7e..1d5b342 100644 --- a/drivers/crypto/Kconfig +++ b/drivers/crypto/Kconfig @@ -325,6 +325,11 @@ config CRYPTO_DEV_TALITOS2 config CRYPTO_DEV_IXP4XX tristate "Driver for IXP4xx crypto hardware acceleration" depends on ARCH_IXP4XX && IXP4XX_QMGR && IXP4XX_NPE + select CRYPTO_AES + select CRYPTO_DES + select CRYPTO_ECB + select CRYPTO_CBC + select CRYPTO_CTR select CRYPTO_LIB_DES select CRYPTO_AEAD select CRYPTO_AUTHENC diff --git a/drivers/crypto/ixp4xx_crypto.c b/drivers/crypto/ixp4xx_crypto.c index f577ee4..8bbf2ea 100644 --- a/drivers/crypto/ixp4xx_crypto.c +++ b/drivers/crypto/ixp4xx_crypto.c @@ -151,6 +151,7 @@ struct ablk_ctx { struct buffer_desc *dst; u8 iv[MAX_IVLEN]; bool encrypt; + struct skcipher_request fallback_req; // keep at the end }; struct aead_ctx { @@ -186,6 +187,7 @@ struct ixp_ctx { unsigned salted; atomic_t configuring; struct completion completion; + struct crypto_skcipher *fallback_tfm; }; struct ixp_alg { @@ -590,7 +592,23 @@ static int init_tfm(struct crypto_tfm *tfm) static int init_tfm_ablk(struct crypto_skcipher *tfm) { - crypto_skcipher_set_reqsize(tfm, sizeof(struct ablk_ctx)); + struct crypto_tfm *ctfm = crypto_skcipher_tfm(tfm); + struct ixp_ctx *ctx = crypto_tfm_ctx(ctfm); + const char *name = crypto_tfm_alg_name(ctfm); + + ctx->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); + if (IS_ERR(ctx->fallback_tfm)) { + pr_err("ERROR: Cannot allocate fallback for %s %ld\n", + name, PTR_ERR(ctx->fallback_tfm)); + return PTR_ERR(ctx->fallback_tfm); + } + + pr_info("Fallback for %s is %s\n", + crypto_tfm_alg_driver_name(&tfm->base), + crypto_tfm_alg_driver_name(crypto_skcipher_tfm(ctx->fallback_tfm)) + ); + + crypto_skcipher_set_reqsize(tfm, sizeof(struct ablk_ctx) + crypto_skcipher_reqsize(ctx->fallback_tfm)); return init_tfm(crypto_skcipher_tfm(tfm)); } @@ -609,6 +627,10 @@ static void exit_tfm(struct crypto_tfm *tfm) static void exit_tfm_ablk(struct crypto_skcipher *tfm) { + struct crypto_tfm *ctfm = crypto_skcipher_tfm(tfm); + struct ixp_ctx *ctx = crypto_tfm_ctx(ctfm); + + crypto_free_skcipher(ctx->fallback_tfm); exit_tfm(crypto_skcipher_tfm(tfm)); } @@ -854,7 +876,12 @@ static int ablk_setkey(struct crypto_skcipher *tfm, const u8 *key, out: if (!atomic_dec_and_test(&ctx->configuring)) wait_for_completion(&ctx->completion); - return ret; + if (ret) + return ret; + crypto_skcipher_clear_flags(ctx->fallback_tfm, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(ctx->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); + + return crypto_skcipher_setkey(ctx->fallback_tfm, key, key_len); } static int ablk_des3_setkey(struct crypto_skcipher *tfm, const u8 *key, @@ -880,6 +907,25 @@ static int ablk_rfc3686_setkey(struct crypto_skcipher *tfm, const u8 *key, return ablk_setkey(tfm, key, key_len); } +static int ixp4xx_cipher_fallback(struct skcipher_request *areq, int encrypt) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq); + struct ixp_ctx *op = crypto_skcipher_ctx(tfm); + struct ablk_ctx *rctx = skcipher_request_ctx(areq); + int err; + + skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm); + skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags, + areq->base.complete, areq->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst, + areq->cryptlen, areq->iv); + if (encrypt) + err = crypto_skcipher_encrypt(&rctx->fallback_req); + else + err = crypto_skcipher_decrypt(&rctx->fallback_req); + return err; +} + static int ablk_perform(struct skcipher_request *req, int encrypt) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); @@ -896,6 +942,9 @@ static int ablk_perform(struct skcipher_request *req, int encrypt) gfp_t flags = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : GFP_ATOMIC; + if (sg_nents(req->src) > 1 || sg_nents(req->dst) > 1) + return ixp4xx_cipher_fallback(req, encrypt); + if (qmgr_stat_full(SEND_QID)) return -EAGAIN; if (atomic_read(&ctx->configuring)) @@ -1422,7 +1471,8 @@ static int __init ixp_module_init(void) /* block ciphers */ cra->base.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC | - CRYPTO_ALG_ALLOCATES_MEMORY; + CRYPTO_ALG_ALLOCATES_MEMORY | + CRYPTO_ALG_NEED_FALLBACK; if (!cra->setkey) cra->setkey = ablk_setkey; if (!cra->encrypt) -- 2.7.4