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 <clabbe@xxxxxxxxxxxx>
---
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 11487ac526ff..9dbed5e2e8a5 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -344,6 +344,11 @@ 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 f577ee4afd06..8bbf2ead6e79 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)
--
2.26.3
