Crash on DNS lookup with Unbound in OpenDKIM

[David Bürgin]

Surprise, it is not actually a crash at all, libunbound simply exits
with exit(1)! Cheeky! Is that intentional? I cannot see an indication of
the error anywhere in syslog or anywhere else. This is unexpected
behaviour from a library to say the least.

I set a breakpoint at fatal_exit() in log.c:

(gdb) bt
#0  fatal_exit (format=format at entry=0x7ffff6e0f060 "could not open autotrust file for writing, %s: %s") at util/log.c:322
#1  0x00007ffff6dde5c0 in autr_write_file (env=<optimized out>, tp=0x7fffe405ed30) at validator/autotrust.c:1189
#2  0x00007ffff6dc09ec in autr_process_prime (qstate=<optimized out>, dnskey_rrset=0x7fffe42b1710, tp=<optimized out>, ve=0x7fffe4049990, env=0x7fffe412d600)
    at validator/autotrust.c:2220
#3  process_prime_response.isra.6 (origin=0x7fffe42b1c70, rcode=<optimized out>, id=<optimized out>, vq=<optimized out>, qstate=<optimized out>)
    at validator/validator.c:2958
#4  val_inform_super (qstate=<optimized out>, id=<optimized out>, super=<optimized out>) at validator/validator.c:3108
#5  0x00007ffff6da4815 in mesh_walk_supers (mesh=mesh at entry=0x7fffe42dfc90, mstate=mstate at entry=0x7fffe42ade40) at services/mesh.c:1185
#6  0x00007ffff6db2f27 in mesh_continue (mesh=mesh at entry=0x7fffe42dfc90, mstate=mstate at entry=0x7fffe42ade40, s=<optimized out>, ev=ev at entry=0x7ffff258c9dc)
    at services/mesh.c:1415
#7  0x00007ffff6db2950 in mesh_run (mesh=0x7fffe42dfc90, mstate=0x7fffe42ade40, ev=<optimized out>, e=0x0) at services/mesh.c:1458
#8  0x00007ffff6dc205d in libworker_handle_service_reply (c=<optimized out>, arg=<optimized out>, error=<optimized out>, reply_info=<optimized out>)
    at libunbound/libworker.c:903
#9  0x00007ffff6d91532 in serviced_callbacks (sq=0x7fffe80151f0, error=0, c=0x7fffe434bcd0, rep=0x7ffff258cca0) at services/outside_network.c:1687
#10 0x00007ffff6d9191b in serviced_udp_callback (c=0x7fffe434bcd0, arg=0x7fffe80151f0, error=<optimized out>, rep=0x7ffff258cca0) at services/outside_network.c:2011
#11 0x00007ffff6d90972 in outnet_udp_cb (c=<optimized out>, arg=0x7fffe4319e00, error=<optimized out>, reply_info=0x7ffff258cca0) at services/outside_network.c:538
#12 0x00007ffff6d8bbb2 in comm_point_udp_callback (fd=16, event=<optimized out>, arg=<optimized out>) at util/netevent.c:704
#13 0x00007ffff61258f8 in ?? () from /usr/lib/x86_64-linux-gnu/libevent-2.1.so.6
#14 0x00007ffff612633f in event_base_loop () from /usr/lib/x86_64-linux-gnu/libevent-2.1.so.6
#15 0x00007ffff6d9335a in ub_event_base_dispatch (base=0x7fffe42df7c0) at util/ub_event_pluggable.c:491
#16 comm_base_dispatch (b=<optimized out>) at util/netevent.c:241
#17 0x00007ffff6dccb2d in libworker_dobg.lto_priv.226 (arg=0x7fffe412d5b0) at libunbound/libworker.c:360
#18 0x00007ffff69546db in start_thread (arg=0x7ffff258d700) at pthread_create.c:463
#19 0x00007ffff667d88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

I set the file permissions of the autotrust file to 0777, but libunbound
still exits. Is configuring auto-trust-anchor-file simply an absolute
no-no with libunbound? Should one always use trust-anchor-file instead
(it does work with trust-anchor-file instead of auto-trust-anchor-file)?

Cheers,