crypto/qat: fix out-of-bounds access

This commit fixes
  - bpi_cipher_encrypt to prevent before 'array subscript is
    above array bounds' error
  - bpi_cipher_decrypt to prevent before 'array subscript is
    above array bounds' error

Fixes: d18ab45f7654 ("crypto/qat: support DOCSIS BPI mode")
Cc: stable@dpdk.org
Signed-off-by: Tomasz Jozwiak <tomaszx.jozwiak@intel.com>
Acked-by: Fiona Trahe <fiona.trahe@intel.com>

diff --git a/drivers/crypto/qat/qat_crypto.c b/drivers/crypto/qat/qat_crypto.c
index cff709a..9d8dc77 100644 (file)
--- a/drivers/crypto/qat/qat_crypto.c
+++ b/drivers/crypto/qat/qat_crypto.c
@@ -40,6 +40,10 @@
 #include "adf_transport_access_macros.h"
 
 #define BYTE_LENGTH    8
+/* bpi is only used for partial blocks of DES and AES
+ * so AES block len can be assumed as max len for iv, src and dst
+ */
+#define BPI_MAX_ENCR_IV_LEN ICP_QAT_HW_AES_BLK_SZ
 
 static int
 qat_is_cipher_alg_supported(enum rte_crypto_cipher_algorithm algo,
@@ -92,16 +96,16 @@ bpi_cipher_encrypt(uint8_t *src, uint8_t *dst,
 {
        EVP_CIPHER_CTX *ctx = (EVP_CIPHER_CTX *)bpi_ctx;
        int encrypted_ivlen;
-       uint8_t encrypted_iv[16];
-       int i;
+       uint8_t encrypted_iv[BPI_MAX_ENCR_IV_LEN];
+       uint8_t *encr = encrypted_iv;
 
        /* ECB method: encrypt the IV, then XOR this with plaintext */
        if (EVP_EncryptUpdate(ctx, encrypted_iv, &encrypted_ivlen, iv, ivlen)
                                                                <= 0)
                goto cipher_encrypt_err;
 
-       for (i = 0; i < srclen; i++)
-               *(dst+i) = *(src+i)^(encrypted_iv[i]);
+       for (; srclen != 0; --srclen, ++dst, ++src, ++encr)
+               *dst = *src ^ *encr;
 
        return 0;
 
@@ -121,16 +125,16 @@ bpi_cipher_decrypt(uint8_t *src, uint8_t *dst,
 {
        EVP_CIPHER_CTX *ctx = (EVP_CIPHER_CTX *)bpi_ctx;
        int encrypted_ivlen;
-       uint8_t encrypted_iv[16];
-       int i;
+       uint8_t encrypted_iv[BPI_MAX_ENCR_IV_LEN];
+       uint8_t *encr = encrypted_iv;
 
        /* ECB method: encrypt (not decrypt!) the IV, then XOR with plaintext */
        if (EVP_EncryptUpdate(ctx, encrypted_iv, &encrypted_ivlen, iv, ivlen)
                                                                <= 0)
                goto cipher_decrypt_err;
 
-       for (i = 0; i < srclen; i++)
-               *(dst+i) = *(src+i)^(encrypted_iv[i]);
+       for (; srclen != 0; --srclen, ++dst, ++src, ++encr)
+               *dst = *src ^ *encr;
 
        return 0;