diff options
| author | Evgeniy Polyakov <johnpol@2ka.mipt.ru> | 2007-08-24 23:36:29 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-08-26 18:35:47 -0700 |
| commit | e7c243c925f6d9dcb898504ff24d6650b5cbb3b1 (patch) | |
| tree | f06ae59e206e4876b0326c65811f496a8b1f4bdc /net | |
| parent | 7c8347a91dbbb723d8ed106ec817dabac97f2bbc (diff) | |
[VLAN/BRIDGE]: Fix "skb_pull_rcsum - Fatal exception in interrupt"
I tried to preserve bridging code as it was before, but logic is quite
strange - I think we should free skb on error, since it is already
unshared and thus will just leak.
Herbert Xu states:
> + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
> + goto out;
If this happens it'll be a double-free on skb since we'll
return NF_DROP which makes the caller free it too.
We could return NF_STOLEN to prevent that but I'm not sure
whether that's correct netfilter semantics. Patrick, could
you please make a call on this?
Patrick McHardy states:
NF_STOLEN should work fine here.
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/8021q/vlan_dev.c | 12 | ||||
| -rw-r--r-- | net/bridge/br_netfilter.c | 12 |
2 files changed, 18 insertions, 6 deletions
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 4bab322c9f8f..328759c32d61 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -116,12 +116,22 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type* ptype, struct net_device *orig_dev) { unsigned char *rawp = NULL; - struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data); + struct vlan_hdr *vhdr; unsigned short vid; struct net_device_stats *stats; unsigned short vlan_TCI; __be16 proto; + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) + return -1; + + if (unlikely(!pskb_may_pull(skb, VLAN_HLEN))) { + kfree_skb(skb); + return -1; + } + + vhdr = (struct vlan_hdr *)(skb->data); + /* vlan_TCI = ntohs(get_unaligned(&vhdr->h_vlan_TCI)); */ vlan_TCI = ntohs(vhdr->h_vlan_TCI); diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index fa779874b9dd..3ee2022928e3 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -509,8 +509,14 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb, int (*okfn)(struct sk_buff *)) { struct iphdr *iph; - __u32 len; struct sk_buff *skb = *pskb; + __u32 len = nf_bridge_encap_header_len(skb); + + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) + return NF_STOLEN; + + if (unlikely(!pskb_may_pull(skb, len))) + goto out; if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) { @@ -518,8 +524,6 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb, if (!brnf_call_ip6tables) return NF_ACCEPT; #endif - if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL) - goto out; nf_bridge_pull_encap_header_rcsum(skb); return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn); } @@ -532,8 +536,6 @@ static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb, !IS_PPPOE_IP(skb)) return NF_ACCEPT; - if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL) - goto out; nf_bridge_pull_encap_header_rcsum(skb); if (!pskb_may_pull(skb, sizeof(struct iphdr))) |