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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2016-02-22 20:43:25 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-24 22:11:34 +0300 |
| commit | a8c4a2522a0808c5c2143612909717d1115c40cf (patch) | |
| tree | 630d9bda2a7e98752fbb442f1d1a96d92035ef98 /net/ipv4/ip_output.c | |
| parent | c7dfe3abf40ec9a298884a4c0775062eac27afc9 (diff) | |
| download | linux-a8c4a2522a0808c5c2143612909717d1115c40cf.tar.xz | |
ipv4: only create late gso-skb if skb is already set up with CHECKSUM_PARTIAL
Otherwise we break the contract with GSO to only pass CHECKSUM_PARTIAL
skbs down. This can easily happen with UDP+IPv4 sockets with the first
MSG_MORE write smaller than the MTU, second write is a sendfile.
Returning -EOPNOTSUPP lets the callers fall back into normal sendmsg path,
were we calculate the checksum manually during copying.
Commit d749c9cbffd6 ("ipv4: no CHECKSUM_PARTIAL on MSG_MORE corked
sockets") started to exposes this bug.
Fixes: d749c9cbffd6 ("ipv4: no CHECKSUM_PARTIAL on MSG_MORE corked sockets")
Reported-by: Jiri Benc <jbenc@redhat.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: Wakko Warner <wakko@animx.eu.org>
Cc: Wakko Warner <wakko@animx.eu.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_output.c')
| -rw-r--r-- | net/ipv4/ip_output.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 64878efa045c..565bf64b2b7d 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1236,13 +1236,16 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, if (!skb) return -EINVAL; - cork->length += size; if ((size + skb->len > mtu) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO)) { + if (skb->ip_summed != CHECKSUM_PARTIAL) + return -EOPNOTSUPP; + skb_shinfo(skb)->gso_size = mtu - fragheaderlen; skb_shinfo(skb)->gso_type = SKB_GSO_UDP; } + cork->length += size; while (size > 0) { if (skb_is_gso(skb)) { |