Commit b680a214 authored Nov 18, 2020 by Paolo Abeni Committed by Jakub Kicinski Nov 19, 2020

mptcp: update rtx timeout only if required.



We must start the retransmission timer only there are
pending data in the rtx queue.
Otherwise we can hit a WARN_ON in mptcp_reset_timer(),
as syzbot demonstrated.

Reported-and-tested-by:  <syzbot+42aa53dafb66a07e5a24@syzkaller.appspotmail.com>
Fixes: d9ca1de8 ("mptcp: move page frag allocation in mptcp_sendmsg()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/1a72039f112cae048c44d398ffa14e0a1432db3d.1605737083.git.pabeni@redhat.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent ac75b096

net/mptcp/protocol.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -1261,12 +1261,13 @@ static void mptcp_push_pending(struct sock *sk, unsigned int flags)
		mptcp_push_release(sk, ssk, &info);

		out:
		if (copied) {
		/* start the timer, if it's not pending */
		if (!mptcp_timer_pending(sk))
		mptcp_reset_timer(sk);
		if (copied)
		__mptcp_check_send_data_fin(sk);
		}
		}

		static int mptcp_sendmsg(struct sock sk, struct msghdr msg, size_t len)
		{

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