Comment 6 for bug 1809438

I seem to be affected by the same issue. I get regular DNS query time-outs coinciding with a lot of the following log messages (syslog):

systemd-resolved[1119]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature level UDP.

Eventually systemd-resolved crashes. This happens more frequently (/or only) when connected to wifi.

Trace extracted from an Apport crash report (cause was a segmentation fault):

#0 0x00007efeaa3c62ed in sd_event_source_unref (p=0x1b01030036100326) at ../src/libsystemd/sd-event/sd-event.c:1912
        __PRETTY_FUNCTION__ = "sd_event_source_unref"
#1 0x0000561894e7f162 in dns_query_stop (q=q@entry=0x5618967255b0) at ../src/resolve/resolved-dns-query.c:336
        c = <optimized out>
        __PRETTY_FUNCTION__ = "dns_query_stop"
#2 0x0000561894e7f1d0 in dns_query_complete (q=0x5618967255b0, state=<optimized out>) at ../src/resolve/resolved-dns-query.c:528
        __PRETTY_FUNCTION__ = "dns_query_complete"
#3 0x0000561894e7f33f in on_query_timeout (s=<optimized out>, usec=<optimized out>, userdata=<optimized out>) at ../src/resolve/resolved-dns-query.c:539
        q = <optimized out>
        __PRETTY_FUNCTION__ = "on_query_timeout"
#4 0x00007efeaa3ceb76 in source_dispatch (s=s@entry=0x561896722680) at ../src/libsystemd/sd-event/sd-event.c:3201
        saved_type = SOURCE_TIME_BOOTTIME
        r = <optimized out>
        __PRETTY_FUNCTION__ = "source_dispatch"
        __func__ = "source_dispatch"
#5 0x00007efeaa3ceef1 in sd_event_dispatch (e=e@entry=0x5618966cfcd0) at ../src/libsystemd/sd-event/sd-event.c:3634
        ref = <optimized out>
        p = <optimized out>
        r = <optimized out>
        __PRETTY_FUNCTION__ = "sd_event_dispatch"
#6 0x00007efeaa3d0928 in sd_event_run (e=e@entry=0x5618966cfcd0, timeout=timeout@entry=18446744073709551615) at ../src/libsystemd/sd-event/sd-event.c:3692
        r = 1
        __PRETTY_FUNCTION__ = "sd_event_run"
#7 0x00007efeaa3d0b4f in sd_event_loop (e=0x5618966cfcd0) at ../src/libsystemd/sd-event/sd-event.c:3714
        ref = 0x5618966cfcd0
        r = <optimized out>
        __PRETTY_FUNCTION__ = "sd_event_loop"
#8 0x0000561894e5a22a in run (argv=<optimized out>, argc=<optimized out>) at ../src/resolve/resolved.c:84
        notify_stop = 0x561894ea3d70 "STOPPING=1\nSTATUS=Shutting down..."

Log statement from the kernel log:

traps: systemd-resolve[1162] general protection fault ip:7efeaa3c62ed sp:7ffef7d6f1b0 error:0 in libsystemd-shared-245.so[7efeaa39e000+174000]

(Although the trace started with a notify_stop, the system was not shutdown at the time)

Other details:

Release: Ubuntu 20.04.01 (amd64)
Systemd package version: 245.4-4ubuntu3.4