panic: tcp_output: mbuf chain shorter than expected: 0 + 60 + 28 - 0 != 60 cpuid = 0 time = 208 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0016ad95c0 vpanic() at vpanic+0x1e0/frame 0xfffffe0016ad9620 panic() at panic+0x43/frame 0xfffffe0016ad9680 tcp_output() at tcp_output+0x3fe2/frame 0xfffffe0016ad9850 tcp_timer_rexmt() at tcp_timer_rexmt+0x87d/frame 0xfffffe0016ad98e0 softclock_call_cc() at softclock_call_cc+0x1dd/frame 0xfffffe0016ad99b0 softclock() at softclock+0xa3/frame 0xfffffe0016ad99f0 ithread_loop() at ithread_loop+0x2f2/frame 0xfffffe0016ad9a60 fork_exit() at fork_exit+0xb0/frame 0xfffffe0016ad9ab0 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0016ad9ab0 --- trap 0, rip = 0, rsp = 0, rbp = 0 --- KDB: enter: panic [ thread pid 12 tid 100018 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why