From: Longpeng(Mike) longpeng2@huawei.com
commit b02989f37fc5e865ceeee9070907e4493b3a21e2 upstream.
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: dbaf0624ffa5 ("crypto: add virtio-crypto driver") Reported-by: LABBE 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: Gonglei arei.gonglei@huawei.com Signed-off-by: Longpeng(Mike) longpeng2@huawei.com Link: https://lore.kernel.org/r/20200602070501.2023-2-longpeng2@huawei.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/crypto/virtio/virtio_crypto_algs.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
--- a/drivers/crypto/virtio/virtio_crypto_algs.c +++ b/drivers/crypto/virtio/virtio_crypto_algs.c @@ -350,13 +350,18 @@ __virtio_crypto_skcipher_do_req(struct v 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->cryptlen); + 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", @@ -443,12 +448,12 @@ __virtio_crypto_skcipher_do_req(struct v 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));