Based on the location of the crash, and the circumstances that cause it, my guess is that this will be fixed by
https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=d290630d31f4517ab26392d00753d1397f9a4114 Please could you try that, and get back to us if it doesn't sort the problem? Cheers, Simon. On 13/10/2021 05:03, Eloy Paris wrote: > Sorry, I forgot the backtrace; here it is: > > (gdb) bt > #0 0x0000561772564d46 in lookup_domain (domain=0x561772b1d7a0 > "enterprise.activity.windows.com", flags=flags@entry=128, > lowout=lowout@entry=0x7ffe8a4b63ac, highout=highout@entry=0x7ffe8a4b63b0) > at domain-match.c:234 > #1 0x0000561772532b1e in forward_query (udpfd=5, > udpaddr=udpaddr@entry=0x7ffe8a4b6500, dst_addr=dst_addr@entry=0x7ffe8a4b64e0, > dst_iface=dst_iface@entry=13, header=header@entry=0x561772b1fae0, > plen=plen@entry=49, limit=0x561772b1fce0 "", now=1634091453, > forward=0x0, ad_reqd=0, do_bit=0) at forward.c:258 > #2 0x000056177253387e in receive_query (listen=listen@entry=0x561772b1f400, > now=now@entry=1634091453) at forward.c:1636 > #3 0x0000561772538b7c in check_dns_listeners (now=now@entry=1634091453) at > dnsmasq.c:1810 > #4 0x000056177251888b in main (argc=<optimized out>, argv=<optimized out>) > at dnsmasq.c:1237 > (gdb) > > > On Tue, Oct 12, 2021 at 10:55:22PM -0400, Eloy Paris wrote: >> Hello, >> >> I am experiencing crashes in dnsmasq (2.86). I am able to reproduce it >> though I am not sure about the exact sequence of events -- it happens >> when I enable/disable my Ethernet NIC and disable/enable my wireless >> NIC. >> >> In this use case, dnsmasq provides DNS and DHCP for a virtual machine >> (VM) running on KVM. Something like this: >> >> +-- (Ethernet)-+ >> | | >> Internet + Hypervisor (virbr0) --- VM >> | | >> +--- (Wi-fi)---+ >> >> The interfaces I am enabling and disabling are on the hypervisor >> ("Ethernet" and "Wi-fi" above; virbr0 never goes down). >> >> I guess dnsmasq does not handle gracefully receiving a DNS request from >> the VM when the external interfaces of the hypervisor (Ethernet or >> wi-fi) go down? >> >> Some details below; happy to provide more information if that's not >> enough to get to the bottom of it. >> >> Cheers, >> >> Eloy Paris.- >> >> ---------------------------------------------------------------------- >> >> elparis@chapilu[0]:~$ sudo coredumpctl debug dnsmasq >> [sudo] Mot de passe de elparis : >> PID: 46002 (dnsmasq) >> UID: 65534 (nobody) >> GID: 65534 (nobody) >> Signal: 11 (SEGV) >> Timestamp: Tue 2021-10-12 22:17:33 EDT (11min ago) >> Command Line: /usr/bin/dnsmasq >> --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro >> --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper >> Executable: /usr/bin/dnsmasq >> Control Group: /system.slice/libvirtd.service >> Unit: libvirtd.service >> Slice: system.slice >> Boot ID: a42fe0fbd18649ad8a6951687e2855d8 >> Machine ID: 3d34409507634591951da9abb51a3942 >> Hostname: chapilu >> Storage: >> /var/lib/systemd/coredump/core.dnsmasq.65534.a42fe0fbd18649ad8a6951687e2855d8.46002.1634091453000000.zst >> (present) >> Disk Size: 204.6K >> Message: Process 46002 (dnsmasq) of user 65534 dumped core. >> >> Found module linux-vdso.so.1 with build-id: >> c6d7bcf242640b81aef03f231535fa4c2486c744 >> Found module libffi.so.7 with build-id: >> de60e99f39569d11d09160bbdcd486cedc87d2b6 >> Found module libp11-kit.so.0 with build-id: >> 5314ec746546ada6f442b6fdfae15eab9f6d3cdc >> Found module libcrypto.so.1.1 with build-id: >> 6d23f0a3f354825868d044684fad31d482cc9210 >> Found module libdl.so.2 with build-id: >> 5abc547e7b0949f89f3c0e21ab0c8331a7440a8a >> Found module libcrypt.so.2 with build-id: >> 3743451bdaf36f951f926927633fd964813025d0 >> Found module libnss_systemd.so.2 with build-id: >> 22990ff716d182c427e26b7a3cf94048b55b3e75 >> Found module libnss_files.so.2 with build-id: >> 1a36dfc01d3a1010b2ee79766a24a8090a3266d5 >> Found module libgpg-error.so.0 with build-id: >> ba85170c2d9343ea05eea8fa2048c212ff4ef552 >> Found module libgcrypt.so.20 with build-id: >> db45f5d5e0f7af1e77324fea1885f974619ad268 >> Found module libcap.so.2 with build-id: >> c1674f9082fedd415876b9f7d9712269163259b5 >> Found module liblz4.so.1 with build-id: >> e63600ab23b2f6997f42fac2fa56e1f02ce159a1 >> Found module libzstd.so.1 with build-id: >> 4b10444c1560ebc574af4d5f488b7408b22d450e >> Found module liblzma.so.5 with build-id: >> 8b615460aa230708c5183f16bede67aa0437d95e >> Found module librt.so.1 with build-id: >> 75484da2d6f1515189eefa076e0a40328834cd16 >> Found module ld-linux-x86-64.so.2 with build-id: >> 040cc3dd10461562f177df39e3be2f3704258c3c >> Found module libmnl.so.0 with build-id: >> fdf3a318247060fa3e451d511ebaf23a7396d1dd >> Found module libnfnetlink.so.0 with build-id: >> 273cc877c7b2ff41e88753edda777d7f1c4017ca >> Found module libunistring.so.2 with build-id: >> 015ac6d6bcb60b7d8bea31a80d1941b06e8636ab >> Found module libsystemd.so.0 with build-id: >> f776aaa16b4e2ba7056d01d928e4b2726ffe2b8b >> Found module libpthread.so.0 with build-id: >> 07c8f95b4f3251d08550217ad8a1f31066229996 >> Found module libc.so.6 with build-id: >> 4b406737057708c0e4c642345a703c47a61c73dc >> Found module libgmp.so.10 with build-id: >> e58d34ab389d1b649c24195c2d145e3ff2e58290 >> Found module libhogweed.so.6 with build-id: >> 2d70cff7b1841b4d9ca4e8e7726cd4b944c07fdc >> Found module libnettle.so.8 with build-id: >> 9a878e513c02007598fcf1e2e286c2203f13536e >> Found module libnetfilter_conntrack.so.3 with build-id: >> 0ad526380b1a1986a1e471a84d88d5f2a7fedd80 >> Found module libidn2.so.0 with build-id: >> 1ce2b50ad9f9821c2c629b521cf5a3c99593d332 >> Found module libdbus-1.so.3 with build-id: >> 74f2ab9c60512f3a93c932c3f627564d42e0b11e >> Found module dnsmasq with build-id: >> 17b49d0999133997748526c51d99bf8b932fb79d >> Stack trace of thread 46002: >> #0 0x0000561772564d46 lookup_domain (dnsmasq + 0x55d46) >> #1 0x0000561772532b1e forward_query (dnsmasq + 0x23b1e) >> #2 0x000056177253387e receive_query (dnsmasq + 0x2487e) >> #3 0x0000561772538b7c check_dns_listeners (dnsmasq + >> 0x29b7c) >> #4 0x000056177251888b main (dnsmasq + 0x988b) >> #5 0x00007f85147e4b25 __libc_start_main (libc.so.6 + >> 0x27b25) >> #6 0x00005617725197ae _start (dnsmasq + 0xa7ae) >> >> GNU gdb (GDB) 11.1 >> Copyright (C) 2021 Free Software Foundation, Inc. >> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> >> This is free software: you are free to change and redistribute it. >> There is NO WARRANTY, to the extent permitted by law. >> Type "show copying" and "show warranty" for details. >> This GDB was configured as "x86_64-pc-linux-gnu". >> Type "show configuration" for configuration details. >> For bug reporting instructions, please see: >> <https://www.gnu.org/software/gdb/bugs/>. >> Find the GDB manual and other documentation resources online at: >> <http://www.gnu.org/software/gdb/documentation/>. >> >> For help, type "help". >> Type "apropos word" to search for commands related to "word"... >> Reading symbols from /usr/bin/dnsmasq... >> [New LWP 46002] >> [Thread debugging using libthread_db enabled] >> Using host libthread_db library "/usr/lib/libthread_db.so.1". >> Core was generated by `/usr/bin/dnsmasq >> --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-'. >> Program terminated with signal SIGSEGV, Segmentation fault. >> #0 0x0000561772564d46 in lookup_domain (domain=0x561772b1d7a0 >> "enterprise.activity.windows.com", flags=flags@entry=128, >> lowout=lowout@entry=0x7ffe8a4b63ac, >> highout=highout@entry=0x7ffe8a4b63b0) at domain-match.c:234 >> 234 domain-match.c: Aucun fichier ou dossier de ce type. >> (gdb) >> >> >> _______________________________________________ >> Dnsmasq-discuss mailing list >> Dnsmasq-discuss@lists.thekelleys.org.uk >> https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss > > _______________________________________________ > Dnsmasq-discuss mailing list > Dnsmasq-discuss@lists.thekelleys.org.uk > https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss > _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss
