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| author | Pavel Tikhomirov <ptikhomirov@virtuozzo.com> | 2024-01-11 23:06:40 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-25 15:45:30 -0800 |
| commit | 544add1f1cfb78c3dfa3e6edcf4668f6be5e730c (patch) | |
| tree | 764922fc2dde9c1fbf83d46f830cb04c50c421eb /include | |
| parent | eb4170437f45b91eef518dcb017197b115b52852 (diff) | |
| download | linux-stable-544add1f1cfb78c3dfa3e6edcf4668f6be5e730c.tar.gz linux-stable-544add1f1cfb78c3dfa3e6edcf4668f6be5e730c.tar.bz2 linux-stable-544add1f1cfb78c3dfa3e6edcf4668f6be5e730c.zip | |
netfilter: bridge: replace physindev with physinif in nf_bridge_info
[ Upstream commit 9874808878d9eed407e3977fd11fee49de1e1d86 ]
An skb can be added to a neigh->arp_queue while waiting for an arp
reply. Where original skb's skb->dev can be different to neigh's
neigh->dev. For instance in case of bridging dnated skb from one veth to
another, the skb would be added to a neigh->arp_queue of the bridge.
As skb->dev can be reset back to nf_bridge->physindev and used, and as
there is no explicit mechanism that prevents this physindev from been
freed under us (for instance neigh_flush_dev doesn't cleanup skbs from
different device's neigh queue) we can crash on e.g. this stack:
arp_process
neigh_update
skb = __skb_dequeue(&neigh->arp_queue)
neigh_resolve_output(..., skb)
...
br_nf_dev_xmit
br_nf_pre_routing_finish_bridge_slow
skb->dev = nf_bridge->physindev
br_handle_frame_finish
Let's use plain ifindex instead of net_device link. To peek into the
original net_device we will use dev_get_by_index_rcu(). Thus either we
get device and are safe to use it or we don't get it and drop skb.
Fixes: c4e70a87d975 ("netfilter: bridge: rename br_netfilter.c to br_netfilter_hooks.c")
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netfilter_bridge.h | 4 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h index e927b9a15a55..743475ca7e9d 100644 --- a/include/linux/netfilter_bridge.h +++ b/include/linux/netfilter_bridge.h @@ -42,7 +42,7 @@ static inline int nf_bridge_get_physinif(const struct sk_buff *skb) if (!nf_bridge) return 0; - return nf_bridge->physindev ? nf_bridge->physindev->ifindex : 0; + return nf_bridge->physinif; } static inline int nf_bridge_get_physoutif(const struct sk_buff *skb) @@ -60,7 +60,7 @@ nf_bridge_get_physindev(const struct sk_buff *skb, struct net *net) { const struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); - return nf_bridge ? nf_bridge->physindev : NULL; + return nf_bridge ? dev_get_by_index_rcu(net, nf_bridge->physinif) : NULL; } static inline struct net_device * diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 27998f73183e..763e9264402f 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -295,7 +295,7 @@ struct nf_bridge_info { u8 bridged_dnat:1; u8 sabotage_in_done:1; __u16 frag_max_size; - struct net_device *physindev; + int physinif; /* always valid & non-NULL from FORWARD on, for physdev match */ struct net_device *physoutdev; |