lkml.org 
[lkml]   [2021]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.10 043/215] virtio-net: Add validation for used length
    Date
    From: Xie Yongji <xieyongji@bytedance.com>

    [ Upstream commit ad993a95c508417acdeb15244109e009e50d8758 ]

    This adds validation for used length (might come
    from an untrusted device) to avoid data corruption
    or loss.

    Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
    Acked-by: Jason Wang <jasowang@redhat.com>
    Link: https://lore.kernel.org/r/20210531135852.113-1-xieyongji@bytedance.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/net/virtio_net.c | 20 +++++++++++++-------
    1 file changed, 13 insertions(+), 7 deletions(-)

    diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
    index 286f836a53bf..e2c6c5675ec6 100644
    --- a/drivers/net/virtio_net.c
    +++ b/drivers/net/virtio_net.c
    @@ -660,6 +660,12 @@ static struct sk_buff *receive_small(struct net_device *dev,
    len -= vi->hdr_len;
    stats->bytes += len;

    + if (unlikely(len > GOOD_PACKET_LEN)) {
    + pr_debug("%s: rx error: len %u exceeds max size %d\n",
    + dev->name, len, GOOD_PACKET_LEN);
    + dev->stats.rx_length_errors++;
    + goto err_len;
    + }
    rcu_read_lock();
    xdp_prog = rcu_dereference(rq->xdp_prog);
    if (xdp_prog) {
    @@ -763,6 +769,7 @@ err:
    err_xdp:
    rcu_read_unlock();
    stats->xdp_drops++;
    +err_len:
    stats->drops++;
    put_page(page);
    xdp_xmit:
    @@ -816,6 +823,12 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
    head_skb = NULL;
    stats->bytes += len - vi->hdr_len;

    + if (unlikely(len > truesize)) {
    + pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
    + dev->name, len, (unsigned long)ctx);
    + dev->stats.rx_length_errors++;
    + goto err_skb;
    + }
    rcu_read_lock();
    xdp_prog = rcu_dereference(rq->xdp_prog);
    if (xdp_prog) {
    @@ -943,13 +956,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
    }
    rcu_read_unlock();

    - if (unlikely(len > truesize)) {
    - pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
    - dev->name, len, (unsigned long)ctx);
    - dev->stats.rx_length_errors++;
    - goto err_skb;
    - }
    -
    head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
    metasize);
    curr_skb = head_skb;
    --
    2.30.2


    \
     
     \ /
      Last update: 2021-07-15 20:50    [W:4.061 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site