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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-10-22 00:07:47 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-04 04:35:18 -0800
commit9d65a3cc82f3824bfa145f869b1076b3941463d4 (patch)
treeee0aadcce80d2e73b3aa69db3c1a405efc9de886
parented6b1f4d5446e510d42577f0c55c748ef9cd36c8 (diff)
inet: fix possible memory corruption with UDP_CORK and UFO
[ This is a simplified -stable version of a set of upstream commits. ] This is a replacement patch only for stable which does fix the problems handled by the following two commits in -net: "ip_output: do skb ufo init for peeked non ufo skb as well" (e93b7d748be887cd7639b113ba7d7ef792a7efb9) "ip6_output: do skb ufo init for peeked non ufo skb as well" (c547dbf55d5f8cf615ccc0e7265e98db27d3fb8b) Three frames are written on a corked udp socket for which the output netdevice has UFO enabled. If the first and third frame are smaller than the mtu and the second one is bigger, we enqueue the second frame with skb_append_datato_frags without initializing the gso fields. This leads to the third frame appended regulary and thus constructing an invalid skb. This fixes the problem by always using skb_append_datato_frags as soon as the first frag got enqueued to the skb without marking the packet as SKB_GSO_UDP. The problem with only two frames for ipv6 was fixed by "ipv6: udp packets following an UFO enqueued packet need also be handled by UFO" (2811ebac2521ceac84f2bdae402455baa6a7fb47). Cc: Jiri Pirko <jiri@resnulli.us> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--include/linux/skbuff.h5
-rw-r--r--net/ipv4/ip_output.c2
-rw-r--r--net/ipv6/ip6_output.c2
3 files changed, 7 insertions, 2 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3b71a4e83642..6bd165be52e3 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1316,6 +1316,11 @@ static inline int skb_pagelen(const struct sk_buff *skb)
return len + skb_headlen(skb);
}
+static inline bool skb_has_frags(const struct sk_buff *skb)
+{
+ return skb_shinfo(skb)->nr_frags;
+}
+
/**
* __skb_fill_page_desc - initialise a paged fragment in an skb
* @skb: buffer containing fragment to be initialised
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index a04d872c54f9..7f4ab5d31c16 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -836,7 +836,7 @@ static int __ip_append_data(struct sock *sk,
csummode = CHECKSUM_PARTIAL;
cork->length += length;
- if (((length > mtu) || (skb && skb_is_gso(skb))) &&
+ if (((length > mtu) || (skb && skb_has_frags(skb))) &&
(sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) {
err = ip_ufo_append_data(sk, queue, getfrag, from, length,
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 44df1c92a0d6..2e542d0a8916 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1252,7 +1252,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
skb = skb_peek_tail(&sk->sk_write_queue);
cork->length += length;
if (((length > mtu) ||
- (skb && skb_is_gso(skb))) &&
+ (skb && skb_has_frags(skb))) &&
(sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO)) {
err = ip6_ufo_append_data(sk, getfrag, from, length,