git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From b02989f37fc5e865ceeee9070907e4493b3a21e2 Mon Sep 17 00:00:00 2001
   2 From: "Longpeng(Mike)" <longpeng2@huawei.com>
   3 Date: Tue, 2 Jun 2020 15:04:59 +0800
   4 Subject: crypto: virtio: Fix src/dst scatterlist calculation in __virtio_crypto_skcipher_do_req()
   5
   6 From: Longpeng(Mike) <longpeng2@huawei.com>
   7
   8 commit b02989f37fc5e865ceeee9070907e4493b3a21e2 upstream.
   9
  10 The system will crash when the users insmod crypto/tcrypt.ko with mode=38
  11 ( testing "cts(cbc(aes))" ).
  12
  13 Usually the next entry of one sg will be @sg@ + 1, but if this sg element
  14 is part of a chained scatterlist, it could jump to the start of a new
  15 scatterlist array. Fix it by sg_next() on calculation of src/dst
  16 scatterlist.
  17
  18 Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
  19 Reported-by: LABBE Corentin <clabbe@baylibre.com>
  20 Cc: Herbert Xu <herbert@gondor.apana.org.au>
  21 Cc: "Michael S. Tsirkin" <mst@redhat.com>
  22 Cc: Jason Wang <jasowang@redhat.com>
  23 Cc: "David S. Miller" <davem@davemloft.net>
  24 Cc: virtualization@lists.linux-foundation.org
  25 Cc: linux-kernel@vger.kernel.org
  26 Cc: stable@vger.kernel.org
  27 Link: https://lore.kernel.org/r/20200123101000.GB24255@Red
  28 Signed-off-by: Gonglei <arei.gonglei@huawei.com>
  29 Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
  30 Link: https://lore.kernel.org/r/20200602070501.2023-2-longpeng2@huawei.com
  31 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
  32 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  33
  34 ---
  35  drivers/crypto/virtio/virtio_crypto_algs.c |   15 ++++++++++-----
  36  1 file changed, 10 insertions(+), 5 deletions(-)
  37
  38 --- a/drivers/crypto/virtio/virtio_crypto_algs.c
  39 +++ b/drivers/crypto/virtio/virtio_crypto_algs.c
  40 @@ -350,13 +350,18 @@ __virtio_crypto_skcipher_do_req(struct v
  41         int err;
  42         unsigned long flags;
  43         struct scatterlist outhdr, iv_sg, status_sg, **sgs;
  44 -       int i;
  45         u64 dst_len;
  46         unsigned int num_out = 0, num_in = 0;
  47         int sg_total;
  48         uint8_t *iv;
  49 +       struct scatterlist *sg;
  50
  51         src_nents = sg_nents_for_len(req->src, req->cryptlen);
  52 +       if (src_nents < 0) {
  53 +               pr_err("Invalid number of src SG.\n");
  54 +               return src_nents;
  55 +       }
  56 +
  57         dst_nents = sg_nents(req->dst);
  58
  59         pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
  60 @@ -443,12 +448,12 @@ __virtio_crypto_skcipher_do_req(struct v
  61         vc_sym_req->iv = iv;
  62
  63         /* Source data */
  64 -       for (i = 0; i < src_nents; i++)
  65 -               sgs[num_out++] = &req->src[i];
  66 +       for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
  67 +               sgs[num_out++] = sg;
  68
  69         /* Destination data */
  70 -       for (i = 0; i < dst_nents; i++)
  71 -               sgs[num_out + num_in++] = &req->dst[i];
  72 +       for (sg = req->dst; sg; sg = sg_next(sg))
  73 +               sgs[num_out + num_in++] = sg;
  74
  75         /* Status */
  76         sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));