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<p>Brandon,</p>
<p>I tried reproducing this from your description and failed. </p>
<p>Please provide your dnsmasq configuration, how it was built
(patches to sources, make arguments), your hosts file, and
recompile with proper debug symbols and possibly
-fsanitize=address to obtain line numbers for the crash you're
showing - and ideally you provoke the crash with a debugger
attached, for instance, gdb --args dnsmasq -d [-other -opts]
and then "run", and "backtrace full" once it has crashed.</p>
<p>I have added one long /etc/hosts line and dnsmasq v2.92 (2.92rel2
doesn't seem to be in Git) and v2.93 do not crash for me.</p>
<p>Regards,<br>
Matthias</p>
<p><br>
</p>
<div class="moz-cite-prefix">Am 03.06.26 um 23:39 schrieb brandon
via Dnsmasq-discuss:<br>
</div>
<blockquote type="cite"
cite="mid:19e8f6dc79f.6c1b6ec7540241.5904425228977549268@emergence.ltd">
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
<div
style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10pt;">
<div>Hello DNS Masq,<br>
</div>
<div><br>
</div>
<div>While using dnsmasq as part of libvirt I've noticed that my
/etc/hosts prevents my VMs from starting. I looked through the
system logs and found that it was DNS Masq that was crashing
causing my VMs to not have any network (not even DHCP or any
ip connectivity).<br>
<br>
I'm using NixOS and using StevenBlack hosts to block ads on my
system.<br>
<br>
I sorted /etc/hosts lines by length and then performed a
binary search to cut down the longest lines one by one.</div>
<div><br>
</div>
<div>What I found was that once the lines get to <=57 chars
dnsmasq is able to start with no problems.<br>
</div>
<div><br>
</div>
<div>Please see my change log here for what I've done on my
system:<br>
<a target="_blank"
href="https://github.com/StevenBlack/hosts/compare/master...yuannan:hosts:short"
moz-do-not-send="true" class="moz-txt-link-freetext">https://github.com/StevenBlack/hosts/compare/master...yuannan:hosts:short</a><br>
<br>
<br>
Versions:<br>
- dnsmasq: dnsmasq-2.92rel2<br>
- nixos: NixOS 26.11 (Zokor) x86_64</div>
<div>- kernel: Linux 7.0.10-zen1 x86_64<br>
- libvirt: 12.2.0<br>
<br>
Logs:<br>
```Jun 03 22:21:07 aurelius systemd-coredump[326471]: [🡕]
Process 326466 (dnsmasq) of user 65534 dumped core.</div>
<div> <br>
</div>
<div> Module
/nix/store/s6fgvggs1rh0qq88z64xp2ais3kq19m7-dnsmasq-2.92rel2/bin/dnsmasq
without build-id.<br>
</div>
<div> Module
libncursesw.so.6 without build-id.<br>
</div>
<div> Module
libedit.so.0 without build-id.<br>
</div>
<div> Module
libjansson.so.4 without build-id.<br>
</div>
<div> Module
libxtables.so.12 without build-id.<br>
</div>
<div> Module
libnftnl.so.11 without build-id.<br>
</div>
<div> Module
libmnl.so.0 without build-id.<br>
</div>
<div> Module
libnftables.so.1 without build-id.<br>
</div>
<div> Module
libgmp.so.10 without build-id.<br>
</div>
<div> Module
libhogweed.so.6 without build-id.<br>
</div>
<div> Module
libnettle.so.8 without build-id.<br>
</div>
<div> Module
libnfnetlink.so.0 without build-id.<br>
</div>
<div> Module
libnetfilter_conntrack.so.3 without build-id.<br>
</div>
<div> Module
libidn.so.12 without build-id.<br>
</div>
<div> Stack
trace of thread 326466:<br>
</div>
<div> #0
0x00007351cf89fdcc __pthread_kill_implementation (libc.so.6 +
0x9fdcc)<br>
</div>
<div> #1
0x00007351cf84265e raise (libc.so.6 + 0x4265e)<br>
</div>
<div> #2
0x00007351cf829350 abort (libc.so.6 + 0x29350)<br>
</div>
<div> #3
0x00007351cf82a3c8 __libc_message_impl.cold (libc.so.6 +
0x2a3c8)<br>
</div>
<div> #4
0x00007351cf931b79 __fortify_fail (libc.so.6 + 0x131b79)<br>
</div>
<div> #5
0x00007351cf931444 __chk_fail (libc.so.6 + 0x131444)<br>
</div>
<div> #6
0x00007351cf933193 __strcpy_chk (libc.so.6 + 0x133193)<br>
</div>
<div> #7
0x000064cc6d9f669a read_hostsfile
(/nix/store/s6fgvggs1rh0qq88z64xp2ais3kq19m7-dnsmasq-2.92rel2/bin/dnsmasq
+ 0xf69a)<br>
</div>
<div> #8
0x000064cc6d9f6caf cache_reload
(/nix/store/s6fgvggs1rh0qq88z64xp2ais3kq19m7-dnsmasq-2.92rel2/bin/dnsmasq
+ 0xfcaf)<br>
</div>
<div> #9
0x000064cc6da19a1d clear_cache_and_reload
(/nix/store/s6fgvggs1rh0qq88z64xp2ais3kq19m7-dnsmasq-2.92rel2/bin/dnsmasq
+ 0x32a1d)<br>
</div>
<div> #10
0x000064cc6d9f36b8 main
(/nix/store/s6fgvggs1rh0qq88z64xp2ais3kq19m7-dnsmasq-2.92rel2/bin/dnsmasq
+ 0xc6b8)<br>
</div>
<div> #11
0x00007351cf82b285 __libc_start_call_main (libc.so.6 +
0x2b285)<br>
</div>
<div> #12
0x00007351cf82b338 __libc_start_main@@GLIBC_2.34 (libc.so.6 +
0x2b338)<br>
</div>
<div> #13
0x000064cc6d9f4245 _start
(/nix/store/s6fgvggs1rh0qq88z64xp2ais3kq19m7-dnsmasq-2.92rel2/bin/dnsmasq
+ 0xd245)<br>
</div>
<div> ELF
object binary architecture: AMD x86-64<br>
</div>
<div>```<br>
<br>
Please let me know if there is anything else you need from me,
thanks.</div>
<div><br>
</div>
<div class="zmail_signature_below">
<div id="" data-zbluepencil-ignore="true"
data-sigid="4659405000000159007">
<div>Brandon Lin<br>
</div>
<div>Managing Director - Emergence Technologies Ltd<br>
</div>
</div>
</div>
<div><br>
</div>
</div>
<br>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
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