On 2020/5/25 上午8:56, Longpeng(Mike) wrote:
The system will crash when we insmod crypto/tcrypt.ko whit mode=38.
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. Let's fix it by sg_next() on calculation of src/dst
scatterlist.
BTW I add a check for sg_nents_for_len() its return value since
sg_nents_for_len() function could fail.
Cc: Gonglei <arei.gonglei@xxxxxxxxxx>
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
Reported-by: LABBE Corentin <clabbe@xxxxxxxxxxxx>
Signed-off-by: Gonglei <arei.gonglei@xxxxxxxxxx>
Signed-off-by: Longpeng(Mike) <longpeng2@xxxxxxxxxx>
---
drivers/crypto/virtio/virtio_crypto_algs.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index 372babb44112..2fa1129f96d6 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -359,8 +359,14 @@ __virtio_crypto_skcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
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",
@@ -446,12 +452,12 @@ __virtio_crypto_skcipher_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, i = 0; sg && i < src_nents; sg = sg_next(sg), i++)
Any reason sg is checked here?
I believe it should be checked in sg_nents_for_len().
+ 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, i = 0; sg && i < dst_nents; sg = sg_next(sg), i++)
+ sgs[num_out + num_in++] = sg;
I believe sg should be checked in sg_nents().
Thanks
/* Status */
sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
