lkml.org 
[lkml]   [2018]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 102/124] ipv4: remove BUG_ON() from fib_compute_spec_dst
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

    [ Upstream commit 9fc12023d6f51551d6ca9ed7e02ecc19d79caf17 ]

    Remove BUG_ON() from fib_compute_spec_dst routine and check
    in_dev pointer during flowi4 data structure initialization.
    fib_compute_spec_dst routine can be run concurrently with device removal
    where ip_ptr net_device pointer is set to NULL. This can happen
    if userspace enables pkt info on UDP rx socket and the device
    is removed while traffic is flowing

    Fixes: 35ebf65e851c ("ipv4: Create and use fib_compute_spec_dst() helper")
    Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    net/ipv4/fib_frontend.c | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    --- a/net/ipv4/fib_frontend.c
    +++ b/net/ipv4/fib_frontend.c
    @@ -289,19 +289,19 @@ __be32 fib_compute_spec_dst(struct sk_bu
    return ip_hdr(skb)->daddr;

    in_dev = __in_dev_get_rcu(dev);
    - BUG_ON(!in_dev);

    net = dev_net(dev);

    scope = RT_SCOPE_UNIVERSE;
    if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) {
    + bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev);
    struct flowi4 fl4 = {
    .flowi4_iif = LOOPBACK_IFINDEX,
    .flowi4_oif = l3mdev_master_ifindex_rcu(dev),
    .daddr = ip_hdr(skb)->saddr,
    .flowi4_tos = RT_TOS(ip_hdr(skb)->tos),
    .flowi4_scope = scope,
    - .flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0,
    + .flowi4_mark = vmark ? skb->mark : 0,
    };
    if (!fib_lookup(net, &fl4, &res, 0))
    return FIB_RES_PREFSRC(net, res);

    \
     
     \ /
      Last update: 2018-08-04 11:14    [W:4.195 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site