examples: gcoap: stack overflow when NON times out #8981
Description
Description
When I send a NON GET with the gcoap example the coap thread overflows if there is no request.
Steps to reproduce the issue
- Flash gcoap example to board (I used
samr21-xpro, did not check for other types of boards) - Check current stack usage:
> ps
2018-04-19 11:26:19,614 - INFO # ps
2018-04-19 11:26:19,622 - INFO # pid | name | state Q | pri | stack ( used) | base addr | current
2018-04-19 11:26:19,630 - INFO # - | isr_stack | - - | - | 512 ( 148) | 0x20000000 | 0x200001b8
2018-04-19 11:26:19,638 - INFO # 1 | idle | pending Q | 15 | 256 ( 156) | 0x200006c0 | 0x20000724
2018-04-19 11:26:19,646 - INFO # 2 | main | running Q | 7 | 1536 ( 1040) | 0x200007c0 | 0x20000c04
2018-04-19 11:26:19,655 - INFO # 3 | 6lo | bl rx _ | 3 | 1024 ( 460) | 0x200036a0 | 0x2000396c
2018-04-19 11:26:19,663 - INFO # 4 | ipv6 | bl rx _ | 4 | 1024 ( 432) | 0x20001764 | 0x20001a2c
2018-04-19 11:26:19,671 - INFO # 5 | udp | bl rx _ | 5 | 1024 ( 272) | 0x20003e6c | 0x2000415c
2018-04-19 11:26:19,680 - INFO # 6 | coap | bl mbox _ | 6 | 1024 ( 776) | 0x200012c4 | 0x200013bc
2018-04-19 11:26:19,688 - INFO # 7 | at86rf2xx | bl rx _ | 2 | 1024 ( 504) | 0x20000e84 | 0x20001174
2018-04-19 11:26:19,694 - INFO # | SUM | | | 7424 ( 3788)
Send CoAP NON to fake destination:
> coap get affe::1 5683 /test
2018-04-19 11:32:47,258 - INFO # coap get affe::1 5683 /test
2018-04-19 11:32:47,262 - INFO # gcoap_cli: sending msg ID 22606, 11 bytes
> 2018-04-19 11:32:52,271 - INFO # gcoap: timeout for msg ID 22606
Check stack usage again:
ps
2018-04-19 11:32:55,406 - INFO # ps
2018-04-19 11:32:55,414 - INFO # pid | name | state Q | pri | stack ( used) | base addr | current
2018-04-19 11:32:55,422 - INFO # - | isr_stack | - - | - | 512 ( 164) | 0x20000000 | 0x200001b8
2018-04-19 11:32:55,430 - INFO # 1 | idle | pending Q | 15 | 256 ( 156) | 0x200006c0 | 0x20000724
2018-04-19 11:32:55,439 - INFO # 2 | main | running Q | 7 | 1536 ( 1052) | 0x200007c0 | 0x20000c04
2018-04-19 11:32:55,447 - INFO # 3 | 6lo | bl rx _ | 3 | 1024 ( 460) | 0x200036a0 | 0x2000396c
2018-04-19 11:32:55,455 - INFO # 4 | ipv6 | bl rx _ | 4 | 1024 ( 432) | 0x20001764 | 0x20001a2c
2018-04-19 11:32:55,463 - INFO # 5 | udp | bl rx _ | 5 | 1024 ( 328) | 0x20003e6c | 0x2000415c
2018-04-19 11:32:55,472 - INFO # 6 | coap | bl mbox _ | 6 | 1024 ( 1024) | 0x200012c4 | 0x200013bc
2018-04-19 11:32:55,480 - INFO # 7 | �D | bl rx _ | 2 | 279 ( -241) | 0x20000e84 | 0x20001174
2018-04-19 11:32:55,486 - INFO # | SUM | | | 6679 ( 3375)
Expected results
Stack should not overflow.
Actual results
Stack overflows and overwrites TCB of following thread (might cause crash later on).
Versions
This was done on 689333f of RIOT.