systemd-resolved dumps core all the time

[Václav Haisman]

It dumps core all the time.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: systemd 245.4-4ubuntu3.1
ProcVersionSignature: Ubuntu 5.4.0-33.37-generic 5.4.34
Uname: Linux 5.4.0-33-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.2
Architecture: amd64
CasperMD5CheckResult: skip
Date: Mon Jun 8 16:51:11 2020
ExecutablePath: /usr/lib/systemd/systemd-resolved
InstallationDate: Installed on 2019-09-30 (252 days ago)
InstallationMedia: Kubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
MachineType: Dell Inc. Precision 5530
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-33-generic root=/dev/mapper/kubuntu--vg-root ro quiet splash vt.handoff=7
SourcePackage: systemd
SystemdDelta:
 [EXTENDED] /usr/lib/systemd/system/rc-local.service → /usr/lib/systemd/system/rc-local.service.d/debian.conf
 [EXTENDED] /usr/lib/systemd/system/user@.service → /usr/lib/systemd/system/user@.service.d/timeout.conf

 2 overridden configuration files found.
UpgradeStatus: Upgraded to focal on 2020-05-28 (11 days ago)
dmi.bios.date: 08/22/2019
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.13.0
dmi.board.name: 0FP2W2
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.13.0:bd08/22/2019:svnDellInc.:pnPrecision5530:pvr:rvnDellInc.:rn0FP2W2:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: Precision
dmi.product.name: Precision 5530
dmi.product.sku: 087D
dmi.sys.vendor: Dell Inc.
mtime.conffile..etc.systemd.logind.conf: 2019-11-18T09:50:53.885999
mtime.conffile..etc.systemd.resolved.conf: 2020-06-04T14:51:08.011600

[Václav Haisman (vzeman79)]

systemd-resolved dumps core resulting in DNS resolution failures in applications.

[Václav Haisman (vzeman79)]

Here is a call stack that I get from gdb:

Reading symbols from /usr/lib/systemd/systemd-resolved...
Reading symbols from /usr/lib/debug/.build-id/bb/f07ab7990febf6bbea9cd22392b488187515fb.debug...
[New LWP 1752251]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `/lib/systemd/systemd-resolved'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f62ef3321fa in hashmap_iterate_entry (h=h@entry=0x706f746b73656465, i=i@entry=0x7fffd2814cc0) at ../src/basic/hashmap.c:706
706 ../src/basic/hashmap.c: No such file or directory.
(gdb) bt
#0 0x00007f62ef3321fa in hashmap_iterate_entry (h=h@entry=0x706f746b73656465, i=i@entry=0x7fffd2814cc0) at ../src/basic/hashmap.c:706
#1 0x00007f62ef334122 in internal_hashmap_iterate (h=0x706f746b73656465, i=i@entry=0x7fffd2814cc0, value=value@entry=0x7fffd2814cb8, key=key@entry=0x0) at ../src/basic/hashmap.c:715
#2 0x00007f62ef3341d7 in set_iterate (s=<optimized out>, i=i@entry=0x7fffd2814cc0, value=value@entry=0x7fffd2814cb8) at ../src/basic/hashmap.c:736
#3 0x000055b8fbc76c67 in dns_query_candidate_go (c=c@entry=0x55b8fd390bb0) at ../src/resolve/resolved-dns-query.c:152
#4 0x000055b8fbc75dfc in dns_query_candidate_notify (c=c@entry=0x55b8fd390bb0) at ../src/resolve/resolved-dns-query.c:312
#5 0x000055b8fbc76058 in dns_transaction_complete (t=t@entry=0x55b8fd394ec0, state=state@entry=DNS_TRANSACTION_RCODE_FAILURE) at ../src/resolve/resolved-dns-transaction.c:350
#6 0x000055b8fbc76a1d in dns_transaction_process_dnssec (t=0x55b8fd394ec0) at ../src/resolve/resolved-dns-transaction.c:832
#7 0x000055b8fbc6f9b6 in dns_transaction_process_reply (t=t@entry=0x55b8fd394ec0, p=p@entry=0x55b8fd39e210) at ../src/resolve/resolved-dns-transaction.c:1194
#8 0x000055b8fbc703ab in on_dns_packet (s=<optimized out>, fd=<optimized out>, revents=<optimized out>, userdata=0x55b8fd394ec0) at ../src/resolve/resolved-dns-transaction.c:1248
#9 0x00007f62ef2a4507 in source_dispatch (s=s@entry=0x55b8fd392260) at ../src/libsystemd/sd-event/sd-event.c:3193
#10 0x00007f62ef2a47a1 in sd_event_dispatch (e=e@entry=0x55b8fd37bf30) at ../src/libsystemd/sd-event/sd-event.c:3634
#11 0x00007f62ef2a61d8 in sd_event_run (e=e@entry=0x55b8fd37bf30, timeout=timeout@entry=18446744073709551615) at ../src/libsystemd/sd-event/sd-event.c:3692
#12 0x00007f62ef2a63f7 in sd_event_loop (e=0x55b8fd37bf30) at ../src/libsystemd/sd-event/sd-event.c:3714
#13 0x000055b8fbc4fb8a in run (argv=<optimized out>, argc=<optimized out>) at ../src/resolve/resolved.c:84
#14 main (argc=<optimized out>, argv=<optimized out>) at ../src/resolve/resolved.c:91

[Václav Haisman (vzeman79)]

(gdb) frame 0
#0 0x00007f62ef3321fa in hashmap_iterate_entry (h=h@entry=0x706f746b73656465, i=i@entry=0x7fffd2814cc0) at ../src/basic/hashmap.c:706
706 in ../src/basic/hashmap.c
(gdb) p *i
$7 = {idx = 4294967295, next_key = 0x0}
(gdb) p/x *i
$8 = {idx = 0xffffffff, next_key = 0x0}
(gdb) p/x *h
Cannot access memory at address 0x706f746b73656465
(gdb) p $_siginfo._sifields._sigfault.si_addr
$9 = (void *) 0x0

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Edward Peek (edwardpeek-crown)]

Seeing this frequently too after adding multiple entries to "Domains" in "/etc/systemd/resolved.conf"

[Edward Peek (edwardpeek-crown)]

Can most rapidly reproduce with a config like:

[Resolve]
Domains=domaina domainb
DNSSEC=yes

And querying a "hostc" that exists under "domainb" only. Will reliably fail after about 5-20 invocations of "resolvectl query hostc".

[Dan Streetman (ddstreet)]

please reopen if this is still an issue

[Launchpad Janitor (janitor)]

[Expired for systemd (Ubuntu) because there has been no activity for 60 days.]