Hi Jason, On 2020/5/25 11:12, Jason Wang wrote: > > 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(). > Do you means: for (sg = req->src, i = 0; i < src_nents; sg = sg_next(sg), i++) ? > >> + 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(). > How about for (sg = req->dst; sg; sg = sg_next(sg)) ? > Thanks > > >> /* Status */ >> sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status)); > > . > -- --- Regards, Longpeng(Mike)