Hans Dedecker
2017-12-01 15:56:46 UTC
Hi Simon,
I've been playing around with dnsmasq configured in strict-order dns
forwarding mode. If all configured dns servers return refused in
response to a query; dnsmasq will end up in an infinite loop
retransmitting the dns query resulting into high CPU load.
Problem is caused by the dns refuse retransmission logic which does
not check for the end of a dns server list iteration in strict mode.
Having one configured dns server returning a refused reply easily
triggers this problem in strict order mode.
I'm working on a patch to fix the issue as the problem is a side
effect of a patch submitted by me
[http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=9396752c115b3ab733fa476b30da73237e12e7ba]
Hans
I've been playing around with dnsmasq configured in strict-order dns
forwarding mode. If all configured dns servers return refused in
response to a query; dnsmasq will end up in an infinite loop
retransmitting the dns query resulting into high CPU load.
Problem is caused by the dns refuse retransmission logic which does
not check for the end of a dns server list iteration in strict mode.
Having one configured dns server returning a refused reply easily
triggers this problem in strict order mode.
I'm working on a patch to fix the issue as the problem is a side
effect of a patch submitted by me
[http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=9396752c115b3ab733fa476b30da73237e12e7ba]
Hans