diff options
| author | Stephen Hemminger <shemminger@osdl.org> | 2006-12-18 20:51:43 +0100 |
|---|---|---|
| committer | Adrian Bunk <bunk@stusta.de> | 2006-12-18 20:51:43 +0100 |
| commit | d0354e3ba19cdf9acc2ca89bbb59b1e6292a4f44 (patch) | |
| tree | e2de02bc6b0b1f1f67f33608bbbd9cf83c73c638 /include | |
| parent | 17735bd9822900d82278842f6bbe7a0e1c64c3b1 (diff) | |
bridge-netfilter: don't overwrite memory outside of skb
The bridge netfilter code needs to check for space at the
front of the skb before overwriting; otherwise if skb from
device doesn't have headroom, then it will cause random
memory corruption.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netfilter_bridge.h | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h index de4d397865c..52502000bbc 100644 --- a/include/linux/netfilter_bridge.h +++ b/include/linux/netfilter_bridge.h @@ -65,16 +65,25 @@ struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb) } /* Only used in br_forward.c */ -static inline -void nf_bridge_maybe_copy_header(struct sk_buff *skb) +static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb) { + int err; + if (skb->nf_bridge) { if (skb->protocol == __constant_htons(ETH_P_8021Q)) { + err = skb_cow(skb, 18); + if (err) + return err; memcpy(skb->data - 18, skb->nf_bridge->data, 18); skb_push(skb, 4); - } else + } else { + err = skb_cow(skb, 16); + if (err) + return err; memcpy(skb->data - 16, skb->nf_bridge->data, 16); + } } + return 0; } static inline |