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authorEric Dumazet <edumazet@google.com>2017-03-23 12:39:21 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-02 21:19:51 -0700
commit428b3cefab22d21013c2a03b8153eefe3df1f576 (patch)
treef3ba5bce77c0b351b9f4c486220781d284c4cc2e /net/core
parent592d0e60a2b76b0a8ea7161d030aeb6e619ab013 (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>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/neighbour.c3
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);
}