I recorded pcap and captured moment just before crash. It doesnt looks like there was any MDNS at all at this moment, only suspicious is many weird DNS requests. (spinesystems.solutions is my local domain set on pc). Not sure what generated them.
Small snap of these: 02:16:36.658522 IP 127.0.0.1.39766 > 127.0.0.1.53: 17063+ A? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.658626 IP 127.0.0.1.31846 > 127.0.0.53.53: 54480+ A? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.659106 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.659603 IP 127.0.0.53.53 > 127.0.0.1.31846: 54480 NXDomain 0/0/0 (56) 02:16:36.659644 IP 127.0.0.1.53 > 127.0.0.1.54315: 17063 NXDomain 0/0/0 (56) 02:16:36.659660 IP 127.0.0.1.53 > 127.0.0.1.39766: 17063 NXDomain 0/0/0 (56) 02:16:36.660099 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.660603 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.661082 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.661513 IP 127.0.0.53.53 > 127.0.0.1.25474: 60255 NXDomain 0/0/1 (67) 02:16:36.661898 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.662282 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.662778 IP 127.0.0.53.53 > 127.0.0.1.6126: 42840 NXDomain 0/0/0 (56) 02:16:36.663188 IP 127.0.0.1.60869 > 127.0.0.1.53: 47647+ AAAA? xjstkkuhaqclygt.spinesystems.solutions. (56) 02:16:36.663259 IP 127.0.0.1.32600 > 127.0.0.53.53: 10939+ AAAA? xjstkkuhaqclygt.spinesystems.solutions. (56) 02:16:36.663449 IP 127.0.0.1.36798 > 127.0.0.1.53: 30847+ AAAA? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.663481 IP 127.0.0.1.15565 > 127.0.0.53.53: 54137+ AAAA? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.664474 IP 127.0.0.1.47179 > 127.0.0.1.53: 3316+ A? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.664563 IP 127.0.0.1.40056 > 127.0.0.53.53: 55684+ A? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.664969 IP 10.255.255.225.55743 > 10.255.255.1.53: 60614+ [1au] A? roxquromlpczqgh.spinesystems.solutions. (67) 02:16:36.665503 IP 10.255.255.1.53 > 10.255.255.225.55743: 60614 NXDomain 0/1/1 (140) 02:16:36.666994 IP 10.255.255.225.55743 > 10.255.255.1.53: 60614+ A? roxquromlpczqgh.spinesystems.solutions. (56) 02:16:36.667494 IP 10.255.255.1.53 > 10.255.255.225.55743: 60614 NXDomain 0/1/0 (129) Maybe because there is massive timeouts in query to nonexisting domain it triggers this bug like in original issue in systemd ( https://github.com/systemd/systemd/issues/18427 )? In my ISP also all port 53 requests are force-redirected to their DNS, so they might timeout sometimes, instead of NXDomain. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1934221 Title: systemd-resolve segfault Status in systemd package in Ubuntu: Fix Released Status in systemd source package in Focal: New Status in systemd source package in Hirsute: New Status in systemd source package in Impish: Fix Released Bug description: [Impact] * systemd-resolved stops replying to clients on the local LAN. * logging segfault crashes in dmesg: [836786.046514] systemd-resolve[872009]: segfault at 39900000000 ip 0000039900000000 sp 00007ffd7959a6d8 error 14 in systemd-resolved[556398695000+9000] [836786.046524] Code: Bad RIP value. [840887.303994] traps: systemd-resolve[877019] general protection fault ip:55ba402e2594 sp:7ffe8cb6bbb0 error:0 in systemd-resolved[55ba402b5000+40000] [844395.313421] systemd-resolve[878503]: segfault at 208 ip 00005557a249f5fa sp 00007ffe686f5a90 error 6 in systemd-resolved[5557a2472000+40000] [844395.313431] Code: 48 85 c0 74 0e 48 8b 8d 00 01 00 00 48 89 88 00 01 00 00 48 8b 85 00 01 00 00 48 85 c0 0f 84 1d 01 00 00 48 8b 95 f8 00 00 00 <48> 89 90 f8 00 00 00 48 c7 85 00 01 00 00 00 00 00 00 48 c7 85 f8 * The upload backports the upstream fix (https://github.com/systemd/systemd/pull/18832) to Focal & Hirsute. [Test Plan] * Setup /etc/systemd/resolved.conf: [Resolve] DNS=46.182.19.48#dns2.digitalcourage.de 1.1.1.1#cloudflare-dns.com 9.9.9.9#dns.quad9.net DNSSEC=yes DNSOverTLS=opportunistic MulticastDNS=no LLMNR=no Cache=yes DNSStubListener=yes Domains=~. * wait for ~24-48 hours and observe if any crash happens [Where problems could occur] * Any regression would likely cause crashes in systemd-resolved, making it unresponsive to DNS network name requests to local applications. [Other Info] * Reported upstream: https://github.com/systemd/systemd/issues/18427 * Fixed upstream in v248: https://github.com/systemd/systemd/pull/18832 === Original description === systemd-resolve keep crashing and it is very annoying as sometimes it severely interrupt normal dns resolving. Last uploaded report is 2d9e7378-d89b-11eb-9e14-fa163ee63de6 Typical error in dmesg: systemd-resolve[1792202]: segfault at 564ff982f3e0 ip 0000564ff982f3e0 sp 00007ffe2fd0b758 error 15 apport hints me that problem is related to mdns #3 0x00007f3e903c2f11 in sd_event_dispatch () from /lib/systemd/libsystemd-shared-245.so It might be (or not) related that some hosts with mdns in my network have ipv6 enabled. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: systemd 245.4-4ubuntu3.7 ProcVersionSignature: Ubuntu 5.4.0-75.84-generic 5.4.119 Uname: Linux 5.4.0-75-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.18 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu Jul 1 08:22:51 2021 InstallationDate: Installed on 2018-12-05 (938 days ago) InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3) MachineType: System manufacturer System Product Name ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-75-generic root=UUID=54b80d5c-3d61-4919-873f-0d308083e3b9 ro quiet splash vt.handoff=7 SourcePackage: systemd UpgradeStatus: Upgraded to focal on 2020-05-22 (405 days ago) dmi.bios.date: 05/12/2020 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1205 dmi.board.asset.tag: Default string dmi.board.name: ROG STRIX X399-E GAMING dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1205:bd05/12/2020:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnROGSTRIXX399-EGAMING:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.sku: SKU dmi.product.version: System Version dmi.sys.vendor: System manufacturer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1934221/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
