Messages in this thread | | | Date | Sat, 01 Nov 2014 17:06:05 -0400 (EDT) | Subject | Re: [PATCH] ipv4: avoid divide 0 error in tcp_incr_quickack | From | David Miller <> |
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From: Chen Weilong <chenweilong@huawei.com> Date: Fri, 31 Oct 2014 22:50:47 +0800
> From: Weilong Chen <chenweilong@huawei.com> > > We got a problem like this: > [ffff8801c1a05570] machine_kexec at ffffffff81025039 > [ffff8801c1a055d0] crash_kexec at ffffffff8109b253 > [ffff8801c1a056a0] oops_end at ffffffff81442aed > [ffff8801c1a056d0] die at ffffffff81005603 > [ffff8801c1a05700] do_trap at ffffffff81442448 > [ffff8801c1a05760] do_divide_error at ffffffff81002c10 > [ffff8801c1a05888] tcp_send_dupack at ffffffff81385e44 > [ffff8801c1a058c8] tcp_validate_incoming at ffffffff813886b5 > [ffff8801c1a05908] tcp_rcv_state_process at ffffffff8138d0b7 > [ffff8801c1a05958] tcp_child_process at ffffffff81397255 > [ffff8801c1a05988] tcp_v4_do_rcv at ffffffff81395a70 > [ffff8801c1a059d8] tcp_v4_rcv at ffffffff81396fc8 > [ffff8801c1a05a48] ip_local_deliver_finish at ffffffff813746e9 > [ffff8801c1a05a78] ip_local_deliver at ffffffff81374a20 > [ffff8801c1a05aa8] ip_rcv_finish at ffffffff81374389 > [ffff8801c1a05ad8] ip_rcv at ffffffff81374c78 > There was a wrong ack packet coming during TCP handshake. The socket's state > was TCP_SYN_RECV, its rcv_mss was not initialize yet. So > tcp_send_dupack -> tcp_enter_quickack_mode got a divide 0 error. > This patch add a state check before tcp_enter_quickack_mode. > > Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Can you please resubmit this, properly CC:'ing netdev@vger.kernel.org this time?
Thank you.
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