请教在线的大佬，这个mqtt0总是在出现这个情况后死掉

I/mqtt] MQTT server connect success.
[I/mqtt] Subscribe #0 /a1JoHB4pAFh/xiayu/user/get OK!
[D/mqtt.sample] inter mqtt_online_callback!
[E/mqtt] [68789] wait Ping Response res: 0
[E/at.clnt] execute command (AT+QISEND=0,2) failed!
[D/mqtt.sample] inter mqtt_offline_callback!
[E/at.m26|mc20] socket (0) close failed, wait close OK timeout.
[E/at.skt] AT socket (0) closesocket failed!
[I/at.m26|mc20] URC data : Call Ready
[D/mqtt] restart!
[D/mqtt.sample] inter mqtt_connect_callback!
[D/mqtt] ipv4 address port: 1883
[D/mqtt] HOST = 'a1JoHB4pAFh.iot-as-mqtt.cn-shanghai.aliyuncs.com'
psr: 0x41000000
r00: 0x00000000
r01: 0x20000f60
r02: 0x20000f44
r03: 0xffffffff
r04: 0x3442486f
r05: 0x68464170
r06: 0x746f692e
r07: 0x2d73612d
r08: 0x7474716d
r09: 0x2d6e632e
r10: 0x6e616873
r11: 0x0000075b
r12: 0x00000000
 lr: 0x08000f69
 pc: 0xa0000000
hard fault on thread: mqtt0
thread           pri  status      sp     stack size max used left tick  error
---------------- ---  ------- ---------- ----------  ------  ---------- ---
mqtt0             10  running 0x000001ac 0x00002000    09%   0x00000002 000
tshell            20  suspend 0x00000138 0x00001000    07%   0x00000006 000
at_clnt0           9  suspend 0x000000ac 0x00000600    20%   0x00000002 000
tidle0            31  ready   0x00000044 0x00000200    17%   0x0000001b 000
mem manage fault:
SCB_CFSR_MFSR:0x01 IACCVIOL