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authorEric Dumazet <edumazet@google.com>2014-02-20 10:09:18 -0800
committerJiri Slaby <jslaby@suse.cz>2014-03-13 23:19:38 +0100
commit10bbbd58f309101e93643637f784ee069785ace2 (patch)
tree425640eaac665ecd5a46a5badffaf13692896905 /net/ipv4/tcp_output.c
parentcbf5a3f6866d1bd105da94090ce7446ef20c610b (diff)
net-tcp: fastopen: fix high order allocations
[ Upstream commit f5ddcbbb40aa0ba7fbfe22355d287603dbeeaaac ] This patch fixes two bugs in fastopen : 1) The tcp_sendmsg(..., @size) argument was ignored. Code was relying on user not fooling the kernel with iovec mismatches 2) When MTU is about 64KB, tcp_send_syn_data() attempts order-5 allocations, which are likely to fail when memory gets fragmented. Fixes: 783237e8daf13 ("net-tcp: Fast Open client - sending SYN-data") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Tested-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r--net/ipv4/tcp_output.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index fb8227a8c004..e088932bcfae 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2902,7 +2902,12 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
space = __tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) -
MAX_TCP_OPTION_SPACE;
- syn_data = skb_copy_expand(syn, skb_headroom(syn), space,
+ space = min_t(size_t, space, fo->size);
+
+ /* limit to order-0 allocations */
+ space = min_t(size_t, space, SKB_MAX_HEAD(MAX_TCP_HEADER));
+
+ syn_data = skb_copy_expand(syn, MAX_TCP_HEADER, space,
sk->sk_allocation);
if (syn_data == NULL)
goto fallback;