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@xxxxxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: Jason Wang <jasowang@xxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Message-Id: <20200123101000.GB24255@Red> Signed-off-by: Gonglei <arei.gonglei@xxxxxxxxxx> Signed-off-by: Longpeng(Mike) <longpeng2@xxxxxxxxxx> --- drivers/crypto/virtio/virtio_crypto_algs.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c index fd045e64..5f82435 100644 --- a/drivers/crypto/virtio/virtio_crypto_algs.c +++ b/drivers/crypto/virtio/virtio_crypto_algs.c @@ -350,13 +350,18 @@ static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm, 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", @@ -442,12 +447,12 @@ static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm, 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)); -- 1.8.3.1