Commit bb904f22 authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman

net: neigh: guard against NULL solicit() method

[ Upstream commit 48481c8f ]

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: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5ab9380b
......@@ -875,6 +875,7 @@ static void neigh_probe(struct neighbour *neigh)
if (skb)
skb = skb_copy(skb, GFP_ATOMIC);
write_unlock(&neigh->lock);
if (neigh->ops->solicit)
neigh->ops->solicit(neigh, skb);
atomic_inc(&neigh->probes);
kfree_skb(skb);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment