From ba66bbe5480a012108958a71cff88b23dce84956 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 25 Jul 2016 18:06:12 +0200 Subject: [PATCH] udp: use sk_filter_trim_cap for udp{,6}_queue_rcv_skb After a612769774a3 ("udp: prevent bugcheck if filter truncates packet too much"), there followed various other fixes for similar cases such as f4979fcea7fd ("rose: limit sk_filter trim to payload"). Latter introduced a new helper sk_filter_trim_cap(), where we can pass the trim limit directly to the socket filter handling. Make use of it here as well with sizeof(struct udphdr) as lower cap limit and drop the extra skb->len test in UDP's input path. Signed-off-by: Daniel Borkmann Cc: Willem de Bruijn Acked-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/ipv4/udp.c | 4 +--- net/ipv6/udp.c | 4 +--- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 4aed8fc23d32..e61f7cd65d08 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1581,9 +1581,7 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) udp_lib_checksum_complete(skb)) goto csum_error; - if (sk_filter(sk, skb)) - goto drop; - if (unlikely(skb->len < sizeof(struct udphdr))) + if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) goto drop; udp_csum_pull_header(skb); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index ad5292be17bd..81e2f98b958d 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -618,9 +618,7 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) udp_lib_checksum_complete(skb)) goto csum_error; - if (sk_filter(sk, skb)) - goto drop; - if (unlikely(skb->len < sizeof(struct udphdr))) + if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) goto drop; udp_csum_pull_header(skb);