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Commit 79603e1c authored by Longpeng(Mike)'s avatar Longpeng(Mike) Committed by Greg Kroah-Hartman
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crypto: virtio: Fix src/dst scatterlist calculation in __virtio_crypto_skcipher_do_req() 



[ Upstream commit b02989f37fc5e865ceeee9070907e4493b3a21e2 ]

The system will crash when the users insmod crypto/tcrypt.ko with mode=38
( testing "cts(cbc(aes))" ).

Usually the next entry of one sg will be @sg@ + 1, but if this sg element
is part of a chained scatterlist, it could jump to the start of a new
scatterlist array. Fix it by sg_next() on calculation of src/dst
scatterlist.

Fixes: dbaf0624 ("crypto: add virtio-crypto driver")
Reported-by: default avatarLABBE Corentin <clabbe@baylibre.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200123101000.GB24255@Red


Signed-off-by: default avatarGonglei <arei.gonglei@huawei.com>
Signed-off-by: default avatarLongpeng(Mike) <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20200602070501.2023-2-longpeng2@huawei.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 44009142

drivers/crypto/virtio/virtio_crypto_algs.c

+10 −5
Original line number Diff line number Diff line
@@ -367,13 +367,18 @@ __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req, 
	int err;

	unsigned long flags;

	struct scatterlist outhdr, iv_sg, status_sg, **sgs;

	int i;

	u64 dst_len;

	unsigned int num_out = 0, num_in = 0;

	int sg_total;

	uint8_t *iv;

	struct scatterlist *sg;



	src_nents = sg_nents_for_len(req->src, req->nbytes);

	if (src_nents < 0) {

		pr_err("Invalid number of src SG.\n");

		return src_nents;

	}



	dst_nents = sg_nents(req->dst);



	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
@@ -459,12 +464,12 @@ __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req, 
	vc_sym_req->iv = iv;



	/* Source data */

	for (i = 0; i < src_nents; i++)

		sgs[num_out++] = &req->src[i];

	for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)

		sgs[num_out++] = sg;



	/* Destination data */

	for (i = 0; i < dst_nents; i++)

		sgs[num_out + num_in++] = &req->dst[i];

	for (sg = req->dst; sg; sg = sg_next(sg))

		sgs[num_out + num_in++] = sg;



	/* Status */

	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));