diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-03-23 12:39:21 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-02 21:19:51 -0700 |
| commit | 428b3cefab22d21013c2a03b8153eefe3df1f576 (patch) | |
| tree | f3ba5bce77c0b351b9f4c486220781d284c4cc2e | |
| parent | 592d0e60a2b76b0a8ea7161d030aeb6e619ab013 (diff) | |
net: neigh: guard against NULL solicit() method
[ Upstream commit 48481c8fa16410ffa45939b13b6c53c2ca609e5f ]
Dmitry posted a nice reproducer of a bug triggering in neigh_probe()
when dereferencing a NULL neigh->ops->solicit method.
This can happen for arp_direct_ops/ndisc_direct_ops and similar,
which can be used for NUD_NOARP neighbours (created when dev->header_ops
is NULL). Admin can then force changing nud_state to some other state
that would fire neigh timer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/core/neighbour.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 769cece9b00b..ae92131c4f89 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -859,7 +859,8 @@ static void neigh_probe(struct neighbour *neigh) if (skb) skb = skb_clone(skb, GFP_ATOMIC); write_unlock(&neigh->lock); - neigh->ops->solicit(neigh, skb); + if (neigh->ops->solicit) + neigh->ops->solicit(neigh, skb); atomic_inc(&neigh->probes); kfree_skb(skb); } |