Date: Tue, 28 Mar 2023 15:30:21 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=270498 Bug ID: 270498 Summary: libc DNS resolver ignore timeout with tcp Product: Base System Version: 13.1-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: bin Assignee: bugs@FreeBSD.org Reporter: email@example.com Created attachment 241157 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=241157&action=edit test program to reproduce the issue The libc resolver functions don't use the timeout with TCP connections. If a TCP connection hangs to the configured name server, the name resolution functions will wait indefinitely and never return to the caller. The timeout option should be used for tcp queries like for udp queries. It looks like linux glibc as the same bug for years https://sourceware.org/bugzilla/show_bug.cgi?id=19643 . I reproduce it on 13.1, but it should be the same with all FreeBSD versions . How-To-Reproduce: The attached C program written by Alain Thivillon <firstname.lastname@example.org> who warn me about this bug can be used to reproduce the issue. It makes a DNS query over tcp to 127.0.0.1:8888 . Launch "nc -l 8888" in a shell and ./test in an other . You will see a connection in the first shell and the test program will be blocked on the DNS query in the second indefinitely or until you answer something or close the nc. -- You are receiving this mail because: You are the assignee for the bug.