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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-10-22 00:07:47 +0200
committerSuren Baghdasaryan <surenb@google.com>2018-03-26 11:31:30 -0700
commit90405c5cd1698393aed20521975813844cf69275 (patch)
tree4bc4d781530d8bf2508de0a0f45c6cb39840160f
parent072f6feeefe632a17a4e473df7315943d1b4f1eb (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). Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Jiri Pirko <jiri@resnulli.us> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Change-Id: Iaa50b451717d4b520ee5a19f355ab41d62422653 Signed-off-by: Suren Baghdasaryan <surenb@google.com>
-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 dec1748cd00..eaf60278163 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1308,6 +1308,11 @@ 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 df906e0846f..c24554fda1c 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -844,7 +844,7 @@ 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 7668f784905..54f17e71f56 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1250,7 +1250,7 @@ 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,