tcp/dccp: block bh before arming time_wait timer
Maciej Żenczykowski reported some panics in tcp_twsk_destructor() that might be caused by the following bug. timewait timer is pinned to the cpu, because we want to transition timwewait refcount from 0 to 4 in one go, once everything has been initialized. At the time commit ed2e9239 ("tcp/dccp: fix timewait races in timer handling") was merged, TCP was always running from BH habdler. After commit 5413d1ba ("net: do not block BH while processing socket backlog") we definitely can run tcp_time_wait() from process context. We need to block BH in the critical section so that the pinned timer has still its purpose. This bug is more likely to happen under stress and when very small RTO are used in datacenter flows. Fixes: 5413d1ba ("net: do not block BH while processing socket backlog") Signed-off-by:Eric Dumazet <edumazet@google.com> Reported-by:
Maciej Żenczykowski <maze@google.com> Acked-by:
Maciej Żenczykowski <maze@google.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
parent
b484d8a5
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