Message ID | 1400960412-12830-1-git-send-email-pch@ordbogen.com |
---|---|
State | Awaiting Upstream, archived |
Delegated to: | David Miller |
Headers | show |
Hello, On Sat, 24 May 2014, Peter Christensen wrote: > Receiving a ICMP response to an IPIP packet in a non-linear skb could > cause a kernel panic in __skb_pull. > > The problem was introduced in > commit f2edb9f7706dcb2c0d9a362b2ba849efe3a97f5e ("ipvs: implement > passive PMTUD for IPIP packets"). > > Signed-off-by: Peter Christensen <pch@ordbogen.com> Thanks! Acked-by: Julian Anastasov <ja@ssi.bg> Simon, please apply to ipvs tree! > --- > net/netfilter/ipvs/ip_vs_core.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c > index 4f26ee4..3d2d2c8 100644 > --- a/net/netfilter/ipvs/ip_vs_core.c > +++ b/net/netfilter/ipvs/ip_vs_core.c > @@ -1392,15 +1392,19 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) > > if (ipip) { > __be32 info = ic->un.gateway; > + __u8 type = ic->type; > + __u8 code = ic->code; > > /* Update the MTU */ > if (ic->type == ICMP_DEST_UNREACH && > ic->code == ICMP_FRAG_NEEDED) { > struct ip_vs_dest *dest = cp->dest; > u32 mtu = ntohs(ic->un.frag.mtu); > + __be16 frag_off = cih->frag_off; > > /* Strip outer IP and ICMP, go to IPIP header */ > - __skb_pull(skb, ihl + sizeof(_icmph)); > + if (pskb_pull(skb, ihl + sizeof(_icmph)) == NULL) > + goto ignore_ipip; > offset2 -= ihl + sizeof(_icmph); > skb_reset_network_header(skb); > IP_VS_DBG(12, "ICMP for IPIP %pI4->%pI4: mtu=%u\n", > @@ -1408,7 +1412,7 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) > ipv4_update_pmtu(skb, dev_net(skb->dev), > mtu, 0, 0, 0, 0); > /* Client uses PMTUD? */ > - if (!(cih->frag_off & htons(IP_DF))) > + if (!(frag_off & htons(IP_DF))) > goto ignore_ipip; > /* Prefer the resulting PMTU */ > if (dest) { > @@ -1427,12 +1431,13 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) > /* Strip outer IP, ICMP and IPIP, go to IP header of > * original request. > */ > - __skb_pull(skb, offset2); > + if (pskb_pull(skb, offset2) == NULL) > + goto ignore_ipip; > skb_reset_network_header(skb); > IP_VS_DBG(12, "Sending ICMP for %pI4->%pI4: t=%u, c=%u, i=%u\n", > &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, > - ic->type, ic->code, ntohl(info)); > - icmp_send(skb, ic->type, ic->code, info); > + type, code, ntohl(info)); > + icmp_send(skb, type, code, info); > /* ICMP can be shorter but anyways, account it */ > ip_vs_out_stats(cp, skb); > > -- > 1.7.10.4 Regards -- Julian Anastasov <ja@ssi.bg> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, May 25, 2014 at 12:16:31AM +0300, Julian Anastasov wrote: > > Hello, > > On Sat, 24 May 2014, Peter Christensen wrote: > > > Receiving a ICMP response to an IPIP packet in a non-linear skb could > > cause a kernel panic in __skb_pull. > > > > The problem was introduced in > > commit f2edb9f7706dcb2c0d9a362b2ba849efe3a97f5e ("ipvs: implement > > passive PMTUD for IPIP packets"). > > > > Signed-off-by: Peter Christensen <pch@ordbogen.com> > > Thanks! > > Acked-by: Julian Anastasov <ja@ssi.bg> > > Simon, please apply to ipvs tree! Thanks, done. -- To unsubscribe from this list: send the line "unsubscribe netdev" 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/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 4f26ee4..3d2d2c8 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -1392,15 +1392,19 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) if (ipip) { __be32 info = ic->un.gateway; + __u8 type = ic->type; + __u8 code = ic->code; /* Update the MTU */ if (ic->type == ICMP_DEST_UNREACH && ic->code == ICMP_FRAG_NEEDED) { struct ip_vs_dest *dest = cp->dest; u32 mtu = ntohs(ic->un.frag.mtu); + __be16 frag_off = cih->frag_off; /* Strip outer IP and ICMP, go to IPIP header */ - __skb_pull(skb, ihl + sizeof(_icmph)); + if (pskb_pull(skb, ihl + sizeof(_icmph)) == NULL) + goto ignore_ipip; offset2 -= ihl + sizeof(_icmph); skb_reset_network_header(skb); IP_VS_DBG(12, "ICMP for IPIP %pI4->%pI4: mtu=%u\n", @@ -1408,7 +1412,7 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) ipv4_update_pmtu(skb, dev_net(skb->dev), mtu, 0, 0, 0, 0); /* Client uses PMTUD? */ - if (!(cih->frag_off & htons(IP_DF))) + if (!(frag_off & htons(IP_DF))) goto ignore_ipip; /* Prefer the resulting PMTU */ if (dest) { @@ -1427,12 +1431,13 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) /* Strip outer IP, ICMP and IPIP, go to IP header of * original request. */ - __skb_pull(skb, offset2); + if (pskb_pull(skb, offset2) == NULL) + goto ignore_ipip; skb_reset_network_header(skb); IP_VS_DBG(12, "Sending ICMP for %pI4->%pI4: t=%u, c=%u, i=%u\n", &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, - ic->type, ic->code, ntohl(info)); - icmp_send(skb, ic->type, ic->code, info); + type, code, ntohl(info)); + icmp_send(skb, type, code, info); /* ICMP can be shorter but anyways, account it */ ip_vs_out_stats(cp, skb);
Receiving a ICMP response to an IPIP packet in a non-linear skb could cause a kernel panic in __skb_pull. The problem was introduced in commit f2edb9f7706dcb2c0d9a362b2ba849efe3a97f5e ("ipvs: implement passive PMTUD for IPIP packets"). Signed-off-by: Peter Christensen <pch@ordbogen.com> --- net/netfilter/ipvs/ip_vs_core.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)