Message ID | 20170217073928.GA25854@breakpoint.cc |
---|---|
State | Accepted |
Delegated to: | Pablo Neira |
Headers | show |
On 17 February 2017 at 15:39, Florian Westphal <fw@strlen.de> wrote: > Daniel J Blueman <daniel@quora.org> wrote: > > [ CC nf-devel, pablo ] > >> When booting a VM in libvirt/KVM attached to a local bridge and KASAN >> enabled on 4.9.10, we see a stream of KASAN warnings about off-slab >> access [1]. >> >> Let me know if you'd like more debug. > > Does this patch help? > > Subject: [PATCH nf] netfilter: use skb_to_full_sk in ip_route_me_harder > > inet_sk(skb->sk) is illegal in case skb is attached to request socket. > > Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") > Reported by: Daniel J Blueman <daniel@quora.org> > Signed-off-by: Florian Westphal <fw@strlen.de> > --- > net/ipv4/netfilter.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c > index b3cc1335adbc..c0cc6aa8cfaa 100644 > --- a/net/ipv4/netfilter.c > +++ b/net/ipv4/netfilter.c > @@ -23,7 +23,8 @@ int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_t > struct rtable *rt; > struct flowi4 fl4 = {}; > __be32 saddr = iph->saddr; > - __u8 flags = skb->sk ? inet_sk_flowi_flags(skb->sk) : 0; > + const struct sock *sk = skb_to_full_sk(skb); > + __u8 flags = sk ? inet_sk_flowi_flags(sk) : 0; > struct net_device *dev = skb_dst(skb)->dev; > unsigned int hh_len; > > @@ -40,7 +41,7 @@ int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_t > fl4.daddr = iph->daddr; > fl4.saddr = saddr; > fl4.flowi4_tos = RT_TOS(iph->tos); > - fl4.flowi4_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0; > + fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0; > if (!fl4.flowi4_oif) > fl4.flowi4_oif = l3mdev_master_ifindex(dev); > fl4.flowi4_mark = skb->mark; > @@ -61,7 +62,7 @@ int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_t > xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) { > struct dst_entry *dst = skb_dst(skb); > skb_dst_set(skb, NULL); > - dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), skb->sk, 0); > + dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0); > if (IS_ERR(dst)) > return PTR_ERR(dst); > skb_dst_set(skb, dst); Apologies for the delays; this also addresses the issue just fine. Tested-by: Daniel J Blueman <daniel@quora.org> Dan
On Mon, Feb 27, 2017 at 10:41:48PM +0800, Daniel J Blueman wrote: > On 17 February 2017 at 15:39, Florian Westphal <fw@strlen.de> wrote: > > Daniel J Blueman <daniel@quora.org> wrote: > > > > [ CC nf-devel, pablo ] > > > >> When booting a VM in libvirt/KVM attached to a local bridge and KASAN > >> enabled on 4.9.10, we see a stream of KASAN warnings about off-slab > >> access [1]. > >> > >> Let me know if you'd like more debug. > > > > Does this patch help? > > > > Subject: [PATCH nf] netfilter: use skb_to_full_sk in ip_route_me_harder > > > > inet_sk(skb->sk) is illegal in case skb is attached to request socket. > > > > Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") > > Reported by: Daniel J Blueman <daniel@quora.org> > > Signed-off-by: Florian Westphal <fw@strlen.de> [...] > Apologies for the delays; this also addresses the issue just fine. > > Tested-by: Daniel J Blueman <daniel@quora.org> Applied, thanks for testing. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c index b3cc1335adbc..c0cc6aa8cfaa 100644 --- a/net/ipv4/netfilter.c +++ b/net/ipv4/netfilter.c @@ -23,7 +23,8 @@ int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_t struct rtable *rt; struct flowi4 fl4 = {}; __be32 saddr = iph->saddr; - __u8 flags = skb->sk ? inet_sk_flowi_flags(skb->sk) : 0; + const struct sock *sk = skb_to_full_sk(skb); + __u8 flags = sk ? inet_sk_flowi_flags(sk) : 0; struct net_device *dev = skb_dst(skb)->dev; unsigned int hh_len; @@ -40,7 +41,7 @@ int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_t fl4.daddr = iph->daddr; fl4.saddr = saddr; fl4.flowi4_tos = RT_TOS(iph->tos); - fl4.flowi4_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0; + fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0; if (!fl4.flowi4_oif) fl4.flowi4_oif = l3mdev_master_ifindex(dev); fl4.flowi4_mark = skb->mark; @@ -61,7 +62,7 @@ int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_t xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) { struct dst_entry *dst = skb_dst(skb); skb_dst_set(skb, NULL); - dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), skb->sk, 0); + dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0); if (IS_ERR(dst)) return PTR_ERR(dst); skb_dst_set(skb, dst);