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Commit 9dda2769 authored by Gerald Schaefer's avatar Gerald Schaefer Committed by Herbert Xu
Browse files

crypto: s390 - Fix aes-xts parameter corruption 



Some s390 crypto algorithms incorrectly use the crypto_tfm structure to
store private data. As the tfm can be shared among multiple threads, this
can result in data corruption.

This patch fixes aes-xts by moving the xts and pcc parameter blocks from
the tfm onto the stack (48 + 96 bytes).

Cc: stable@vger.kernel.org
Signed-off-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 935e99a3

arch/s390/crypto/aes_s390.c

+17 −14
Original line number Diff line number Diff line
@@ -55,8 +55,7 @@ struct pcc_param { 


struct s390_xts_ctx {

	u8 key[32];

	u8 xts_param[16];

	struct pcc_param pcc;

	u8 pcc_key[32];

	long enc;

	long dec;

	int key_len;
@@ -591,7 +590,7 @@ static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 
		xts_ctx->enc = KM_XTS_128_ENCRYPT;

		xts_ctx->dec = KM_XTS_128_DECRYPT;

		memcpy(xts_ctx->key + 16, in_key, 16);

		memcpy(xts_ctx->pcc.key + 16, in_key + 16, 16);

		memcpy(xts_ctx->pcc_key + 16, in_key + 16, 16);

		break;

	case 48:

		xts_ctx->enc = 0;
@@ -602,7 +601,7 @@ static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 
		xts_ctx->enc = KM_XTS_256_ENCRYPT;

		xts_ctx->dec = KM_XTS_256_DECRYPT;

		memcpy(xts_ctx->key, in_key, 32);

		memcpy(xts_ctx->pcc.key, in_key + 32, 32);

		memcpy(xts_ctx->pcc_key, in_key + 32, 32);

		break;

	default:

		*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
@@ -621,29 +620,33 @@ static int xts_aes_crypt(struct blkcipher_desc *desc, long func, 
	unsigned int nbytes = walk->nbytes;

	unsigned int n;

	u8 *in, *out;

	void *param;

	struct pcc_param pcc_param;

	struct {

		u8 key[32];

		u8 init[16];

	} xts_param;



	if (!nbytes)

		goto out;



	memset(xts_ctx->pcc.block, 0, sizeof(xts_ctx->pcc.block));

	memset(xts_ctx->pcc.bit, 0, sizeof(xts_ctx->pcc.bit));

	memset(xts_ctx->pcc.xts, 0, sizeof(xts_ctx->pcc.xts));

	memcpy(xts_ctx->pcc.tweak, walk->iv, sizeof(xts_ctx->pcc.tweak));

	param = xts_ctx->pcc.key + offset;

	ret = crypt_s390_pcc(func, param);

	memset(pcc_param.block, 0, sizeof(pcc_param.block));

	memset(pcc_param.bit, 0, sizeof(pcc_param.bit));

	memset(pcc_param.xts, 0, sizeof(pcc_param.xts));

	memcpy(pcc_param.tweak, walk->iv, sizeof(pcc_param.tweak));

	memcpy(pcc_param.key, xts_ctx->pcc_key, 32);

	ret = crypt_s390_pcc(func, &pcc_param.key[offset]);

	if (ret < 0)

		return -EIO;



	memcpy(xts_ctx->xts_param, xts_ctx->pcc.xts, 16);

	param = xts_ctx->key + offset;

	memcpy(xts_param.key, xts_ctx->key, 32);

	memcpy(xts_param.init, pcc_param.xts, 16);

	do {

		/* only use complete blocks */

		n = nbytes & ~(AES_BLOCK_SIZE - 1);

		out = walk->dst.virt.addr;

		in = walk->src.virt.addr;



		ret = crypt_s390_km(func, param, out, in, n);

		ret = crypt_s390_km(func, &xts_param.key[offset], out, in, n);

		if (ret < 0 || ret != n)

			return -EIO;