On 2/4/19 7:24 AM, Wouter Wijngaards via Unbound-users wrote:
That's not a problem in itself, but I believe Unbound may be occasionally
triggering a false positive failure during capsforid fallback.
Thanks for the detailed report. Yes, you are right, it should get
sorted. I have made a fix, also in the code repository that sorts the
rrsets before comparison.
Thanks very much for writing this patch. I've been doing some local
testing and have found a segfault. To produce the segfault, I used
https://github.com/letsencrypt/dns-lots-of-lookups, which simply does a
lot of lookups for a long list of names. I suspect any long list of name
would do but I can provide an example if it would be helpful.
Stack trace is attached. Binary with debug symbold and core file are at:
https://jacob.hoffman-andrews.com/rrsort-crash/core
https://jacob.hoffman-andrews.com/rrsort-crash/unbound
I've confirmed that reverting this patch fixes the crash.
Thanks,
Jacob
Core was generated by `./unbound -d -c
/home/jsha/gopkg/src/github.com/jsha/unboundtest/unbound.conf'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 dname_count_labels (dname=0x3a6657688 <error: Cannot access memory at
address 0x3a6657688>) at util/data/dname.c:394
394 lablen = *dname++;
[Current thread is 1 (Thread 0x7fcdc698b740 (LWP 23115))]
(gdb) bt
#0 dname_count_labels (dname=0x3a6657688 <error: Cannot access memory at
address 0x3a6657688>) at util/data/dname.c:394
#1 0x0000558673feba13 in dname_canonical_compare (d1=0x55868e4919a0 "",
d2=0x3a6657687 <error: Cannot access memory at address 0x3a6657687>) at
util/data/dname.c:798
#2 0x0000558674009e8c in rrset_canonical_sort_cmp (x=0x55868e4918b0,
y=0x55868e4918b8) at iterator/iter_utils.c:893
#3 0x00007fcdc6fa56b2 in msort_with_tmp (p=p@entry=0x7fff1c910c40,
b=b@entry=0x55868e4918b0, n=n@entry=2) at msort.c:83
#4 0x00007fcdc6fa5402 in msort_with_tmp (n=2, b=0x55868e4918b0,
p=0x7fff1c910c40) at msort.c:53
#5 msort_with_tmp (p=p@entry=0x7fff1c910c40, b=b@entry=0x55868e4918b0,
n=n@entry=4) at msort.c:53
#6 0x00007fcdc6fa5832 in msort_with_tmp (n=4, b=0x55868e4918b0,
p=0x7fff1c910c40) at msort.c:297
#7 __GI___qsort_r (b=0x55868e4918b0, n=4, s=8, cmp=0x558674009e50
<rrset_canonical_sort_cmp>, arg=0x0) at msort.c:297
#8 0x000055867400a078 in reply_equal (p=0x55868e512568, q=0x55868e658278,
region=0x55868e491400) at iterator/iter_utils.c:935
#9 0x0000558673fffc40 in process_response (qstate=0x55868e654770,
iq=0x55868e6549b8, ie=0x5586749964b0, id=1, outbound=0x55868e512508,
event=module_event_reply) at iterator/iterator.c:3735
#10 0x0000558673ffff1b in iter_operate (qstate=0x55868e654770,
event=module_event_reply, id=1, outbound=0x55868e512508) at
iterator/iterator.c:3792
#11 0x0000558674016669 in mesh_run (mesh=0x55868e4a1420, mstate=0x55868e654720,
ev=module_event_reply, e=0x55868e512508) at services/mesh.c:1496
#12 0x0000558674013a79 in mesh_report_reply (mesh=0x55868e4a1420,
e=0x55868e512508, reply=0x55868c5f2458, what=0) at services/mesh.c:640
#13 0x0000558673fdd3f7 in worker_handle_service_reply (c=0x55868c5f2420,
arg=0x55868e512508, error=0, reply_info=0x55868c5f2458) at daemon/worker.c:295
#14 0x000055867408e6db in serviced_callbacks (sq=0x55868e4d6370, error=0,
c=0x55868c5f2420, rep=0x55868c5f2458) at services/outside_network.c:1782
#15 0x000055867408ed1e in serviced_tcp_callback (c=0x55868c5f2420,
arg=0x55868e4d6370, error=0, rep=0x55868c5f2458) at
services/outside_network.c:1873
#16 0x000055867408a7bb in outnet_tcp_cb (c=0x55868c5f2420, arg=0x55868c5f23f0,
error=0, reply_info=0x55868c5f2458) at services/outside_network.c:489
#17 0x00005586740808d6 in tcp_callback_reader (c=0x55868c5f2420) at
util/netevent.c:1015
#18 0x0000558674081c7a in comm_point_tcp_handle_read (fd=183, c=0x55868c5f2420,
short_ok=0) at util/netevent.c:1461
#19 0x00005586740821bf in comm_point_tcp_handle_callback (fd=183, event=2,
arg=0x55868c5f2420) at util/netevent.c:1743
#20 0x00007fcdc6ca08f8 in ?? () from /usr/lib/x86_64-linux-gnu/libevent-2.1.so.6
#21 0x00007fcdc6ca133f in event_base_loop () from
/usr/lib/x86_64-linux-gnu/libevent-2.1.so.6
#22 0x0000558674090aa7 in ub_event_base_dispatch (base=0x558674996c10) at
util/ub_event.c:280
#23 0x000055867407f036 in comm_base_dispatch (b=0x558674996b60) at
util/netevent.c:246
#24 0x0000558673fe27e0 in worker_work (worker=0x558674989fd0) at
daemon/worker.c:1893
#25 0x0000558673fce73e in daemon_fork (daemon=0x558674851260) at
daemon/daemon.c:666
#26 0x0000558673fdc6b5 in run_daemon (cfgfile=0x7fff1c912d0b
"/home/jsha/gopkg/src/github.com/jsha/unboundtest/unbound.conf",
cmdline_verbose=0, debug_mode=1,
log_default_identity=0x7fff1c912cfd "unbound", need_pidfile=1) at
daemon/unbound.c:670
#27 0x0000558673fdc8f6 in main (argc=0, argv=0x7fff1c9113f8) at
daemon/unbound.c:767
