From: Matthieu Baerts matthieu.baerts@tessares.net
[ Upstream commit 04fac2cae9422a3401c172571afbcfdd58fa5c7e ]
When these two options had to be sent -- which is not common -- the DSS size was not being taken into account in the remaining size.
Additionally in this situation, the reported size was only the one of the MP_FAIL which can cause issue if at the end, we need to write more in the TCP options than previously said.
Here we use a dedicated variable for MP_FAIL size to keep the WARN_ON_ONCE() just after.
Fixes: c25aeb4e0953 ("mptcp: MP_FAIL suboption sending") Acked-and-tested-by: Geliang Tang geliang.tang@suse.com Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/options.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index fe98e4f475baa..96c6efdd48bcc 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -821,10 +821,13 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts)) ret = true; else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts)) { + unsigned int mp_fail_size; + ret = true; - if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) { - *size += opt_size; - remaining -= opt_size; + if (mptcp_established_options_mp_fail(sk, &mp_fail_size, + remaining - opt_size, opts)) { + *size += opt_size + mp_fail_size; + remaining -= opt_size - mp_fail_size; return true; } }