From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" Subject: Re: [PATCH 1/2] crypto: virtio: fix src/dst scatterlist calculation Date: Mon, 25 May 2020 11:45:23 +0800 Message-ID: References: <20200525005627.707-1-longpeng2@huawei.com> <20200525005627.707-2-longpeng2@huawei.com> <25cff618-601c-e899-a3cc-b289863a7407@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <25cff618-601c-e899-a3cc-b289863a7407@redhat.com> Content-Language: en-US Sender: linux-crypto-owner@vger.kernel.org To: Jason Wang , linux-crypto@vger.kernel.org Cc: Gonglei , Herbert Xu , "Michael S. Tsirkin" , "David S. Miller" , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, LABBE Corentin List-Id: virtualization@lists.linuxfoundation.org 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 >> Cc: Herbert Xu >> Cc: "Michael S. Tsirkin" >> Cc: Jason Wang >> Cc: "David S. Miller" >> Cc: virtualization@lists.linux-foundation.org >> Cc: linux-kernel@vger.kernel.org >> >> Reported-by: LABBE Corentin >> Signed-off-by: Gonglei >> Signed-off-by: Longpeng(Mike) >> --- >>   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)