This is from v2.90 from the ubuntu packaging:
Stack trace of thread 349999: #0 0x00007f21c90499fc pthread_kill (libc.so.6 + 0x969fc) #1 0x00007f21c8ff5476 raise (libc.so.6 + 0x42476) #2 0x00007f21c8fdb7f3 abort (libc.so.6 + 0x287f3) #3 0x00007f21c903c676 n/a (libc.so.6 + 0x89676) #4 0x00007f21c9053cfc n/a (libc.so.6 + 0xa0cfc) #5 0x00007f21c9055a54 n/a (libc.so.6 + 0xa2a54) #6 0x00007f21c9058453 free (libc.so.6 + 0xa5453) #7 0x000055ea8f653810 dhcp_netid_free (dnsmasq + 0x1b810) #8 0x000055ea8f6538df dhcp_netid_list_free (dnsmasq + 0x1b8df) #9 0x000055ea8f653956 dhcp_config_free (dnsmasq + 0x1b956) #10 0x000055ea8f661868 clear_dynamic_conf (dnsmasq + 0x29868) #11 0x000055ea8f661947 reread_dhcp (dnsmasq + 0x29947) #12 0x000055ea8f6737b7 clear_cache_and_reload (dnsmasq + 0x3b7b7) #13 0x000055ea8f672db5 async_event (dnsmasq + 0x3adb5) #14 0x000055ea8f6725aa main (dnsmasq + 0x3a5aa) #15 0x00007f21c8fdcd90 n/a (libc.so.6 + 0x29d90) #16 0x00007f21c8fdce40 __libc_start_main (libc.so.6 + 0x29e40) #17 0x000055ea8f642bc5 _start (dnsmasq + 0xabc5)
This is from v2.90 from the ubuntu packaging:
#0 0x00007f21c90499fc pthread_kill (libc.so.6 + 0x969fc)
#1 0x00007f21c8ff5476 raise (libc.so.6 + 0x42476)
#2 0x00007f21c8fdb7f3 abort (libc.so.6 + 0x287f3)
#3 0x00007f21c903c676 n/a (libc.so.6 + 0x89676)
#4 0x00007f21c9053cfc n/a (libc.so.6 + 0xa0cfc)
#5 0x00007f21c9055a54 n/a (libc.so.6 + 0xa2a54)
#6 0x00007f21c9058453 free (libc.so.6 + 0xa5453)
#7 0x000055ea8f653810 dhcp_netid_free (dnsmasq + 0x1b810)
#8 0x000055ea8f6538df dhcp_netid_
#9 0x000055ea8f653956 dhcp_config_free (dnsmasq + 0x1b956)
#10 0x000055ea8f661868 clear_dynamic_conf (dnsmasq + 0x29868)
#11 0x000055ea8f661947 reread_dhcp (dnsmasq + 0x29947)
#12 0x000055ea8f6737b7 clear_cache_
#13 0x000055ea8f672db5 async_event (dnsmasq + 0x3adb5)
#14 0x000055ea8f6725aa main (dnsmasq + 0x3a5aa)
#15 0x00007f21c8fdcd90 n/a (libc.so.6 + 0x29d90)
#16 0x00007f21c8fdce40 __libc_start_main (libc.so.6 + 0x29e40)
#17 0x000055ea8f642bc5 _start (dnsmasq + 0xabc5)