net: sched: ife: check on metadata length

This patch checks if sk buffer is available to dererence ife header. If
not then NULL will returned to signal an malformed ife packet. This
avoids to crashing the kernel from outside.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Reviewed-by: Yotam Gigi <yotam.gi@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Aring 2018-04-20 15:15:05 -04:00 committed by David S. Miller
parent cc74eddd0f
commit d57493d6d1
1 changed files with 3 additions and 0 deletions

View File

@ -69,6 +69,9 @@ void *ife_decode(struct sk_buff *skb, u16 *metalen)
int total_pull; int total_pull;
u16 ifehdrln; u16 ifehdrln;
if (!pskb_may_pull(skb, skb->dev->hard_header_len + IFE_METAHDRLEN))
return NULL;
ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len); ifehdr = (struct ifeheadr *) (skb->data + skb->dev->hard_header_len);
ifehdrln = ntohs(ifehdr->metalen); ifehdrln = ntohs(ifehdr->metalen);
total_pull = skb->dev->hard_header_len + ifehdrln; total_pull = skb->dev->hard_header_len + ifehdrln;