Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1607834
| From | Eric Dumazet <eric.dumazet@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH net] net: neigh: guard against NULL solicit() method |
| Date | 2017-03-23 20:40 +0100 |
| Message-ID | <togKu-6RO-7@gated-at.bofh.it> (permalink) |
| References | <toavo-2lS-23@gated-at.bofh.it> <tocnw-3Ak-27@gated-at.bofh.it> <todtg-4AG-19@gated-at.bofh.it> <toghs-6GO-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Eric Dumazet <edumazet@google.com> 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> --- net/core/neighbour.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index e7c12caa20c88acc9a5dd86f07d11644fb58341d..4526cbd7e28a1fcdecfc06a41985fd4d19634457 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -860,7 +860,8 @@ 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); }
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
netlink: NULL timer crash Dmitry Vyukov <dvyukov@google.com> - 2017-03-23 14:00 +0100
Re: netlink: NULL timer crash Eric Dumazet <edumazet@google.com> - 2017-03-23 16:00 +0100
Re: netlink: NULL timer crash Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-23 17:10 +0100
Re: netlink: NULL timer crash David Miller <davem@davemloft.net> - 2017-03-23 20:10 +0100
[PATCH net] net: neigh: guard against NULL solicit() method Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-23 20:40 +0100
Re: [PATCH net] net: neigh: guard against NULL solicit() method David Miller <davem@davemloft.net> - 2017-03-24 05:30 +0100
Re: netlink: NULL timer crash Eric Dumazet <eric.dumazet@gmail.com> - 2017-03-23 20:40 +0100
csiph-web