From 456afe01b10085518406022c69cfd2b718d6eaf8 Mon Sep 17 00:00:00 2001 From: Matthieu Baerts Date: Sat, 3 Oct 2020 17:36:56 +0200 Subject: mptcp: ADD_ADDRs with echo bit are smaller The MPTCP ADD_ADDR suboption with echo-flag=1 has no HMAC, the size is smaller than the one initially sent without echo-flag=1. We then need to use the correct size everywhere when we need this echo bit. Before this patch, the wrong size was reserved but the correct amount of bytes were written (and read): the remaining bytes contained garbage. Fixes: 6a6c05a8b016 ("mptcp: send out ADD_ADDR with echo flag") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/95 Reported-and-tested-by: Davide Caratti Acked-by: Geliang Tang Signed-off-by: Matthieu Baerts Signed-off-by: David S. Miller --- net/mptcp/pm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/mptcp/pm.c') diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 7e81f53d1e5d..e19e1525ecbb 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -183,11 +183,12 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining, if (!mptcp_pm_should_add_signal(msk)) goto out_unlock; - if (remaining < mptcp_add_addr_len(msk->pm.local.family)) + *echo = READ_ONCE(msk->pm.add_addr_echo); + + if (remaining < mptcp_add_addr_len(msk->pm.local.family, *echo)) goto out_unlock; *saddr = msk->pm.local; - *echo = READ_ONCE(msk->pm.add_addr_echo); WRITE_ONCE(msk->pm.add_addr_signal, false); ret = true; -- cgit v1.2.3