ThreadSanitizer: data race in free

Job #1879757 failed for adb1ca6d:

WARNING: ThreadSanitizer: data race 
  Write of size 8 at 0x000000000001 by thread T1 (mutexes: write M1):
    #0 free <null>
    #1 sdallocx lib/isc/./jemalloc_shim.h:39:2
    #2 isc_mem_setwater lib/isc/mem.c:1074:2
    #3 dns_adb_shutdown lib/dns/adb.c:2872:3
    #4 view_flushanddetach lib/dns/view.c:641:4
    #5 dns_view_detach lib/dns/view.c:696:2
    #6 ns_client_endrequest lib/ns/client.c:194:3
    #7 ns__client_reset_cb lib/ns/client.c:1560:2
    #8 nmhandle_detach_cb lib/isc/netmgr/netmgr.c:1828:3
    #9 isc__nmhandle_detach lib/isc/netmgr/netmgr.c:1784:3
    #10 isc___nm_uvreq_put lib/isc/netmgr/netmgr.c:2448:3
    #11 isc__nm_async_sendcb lib/isc/netmgr/netmgr.c:2746:2
    #12 process_netievent lib/isc/netmgr/netmgr.c:960:3
    #13 process_queue lib/isc/netmgr/netmgr.c:998:16
    #14 process_all_queues lib/isc/netmgr/netmgr.c:746:25
    #15 async_cb lib/isc/netmgr/netmgr.c:775:6
    #16 <null> <null>
    #17 isc__trampoline_run lib/isc/trampoline.c:180:11

  Previous read of size 8 at 0x000000000001 by thread T2 (mutexes: write M2, write M3):
    #0 hi_water lib/isc/mem.c:671:13
    #1 isc__mem_get lib/isc/mem.c:737:2
    #2 new_adbaddrinfo lib/dns/adb.c:2029:7
    #3 copy_namehook_lists lib/dns/adb.c:2240:15
    #4 dns_adb_createfind lib/dns/adb.c:3174:2
    #5 findname lib/dns/resolver.c:3481:11
    #6 fctx_getaddresses lib/dns/resolver.c:3791:3
    #7 fctx_try lib/dns/resolver.c:4180:12
    #8 rctx_nextserver lib/dns/resolver.c:9750:2
    #9 rctx_done lib/dns/resolver.c:9896:3
    #10 rctx_dispfail lib/dns/resolver.c:8191:2
    #11 resquery_response lib/dns/resolver.c:7706:11
    #12 task_run lib/isc/task.c:827:5
    #13 isc_task_run lib/isc/task.c:907:10
    #14 isc__nm_async_task lib/isc/netmgr/netmgr.c:827:11
    #15 process_netievent lib/isc/netmgr/netmgr.c:906:3
    #16 process_queue lib/isc/netmgr/netmgr.c:998:16
    #17 process_all_queues lib/isc/netmgr/netmgr.c:746:25
    #18 async_cb lib/isc/netmgr/netmgr.c:775:6
    #19 <null> <null>
    #20 isc__trampoline_run lib/isc/trampoline.c:180:11

  Mutex M1 is already destroyed.

  Mutex M2 is already destroyed.

  Mutex M3 (0x000000000036) created at:
    #0 pthread_mutex_init <null>
    #1 isc__mutex_init lib/isc/mutex.c:288:8
    #2 isc_mutexblock_init lib/isc/mutexblock.c:22:3
    #3 dns_adb_create lib/dns/adb.c:2674:2
    #4 dns_view_createresolver lib/dns/view.c:832:11
    #5 configure_view bin/named/server.c:4741:2
    #6 load_configuration bin/named/server.c:9381:3
    #7 loadconfig bin/named/server.c:10586:11
    #8 reload bin/named/server.c:10609:2
    #9 named_server_reloadcommand bin/named/server.c:10935:12
    #10 named_control_docommand bin/named/control.c:254:12
    #11 control_command bin/named/controlconf.c:392:17
    #12 task_run lib/isc/task.c:827:5
    #13 isc_task_run lib/isc/task.c:907:10
    #14 isc__nm_async_task lib/isc/netmgr/netmgr.c:827:11
    #15 process_netievent lib/isc/netmgr/netmgr.c:906:3
    #16 process_queue lib/isc/netmgr/netmgr.c:998:16
    #17 process_all_queues lib/isc/netmgr/netmgr.c:746:25
    #18 async_cb lib/isc/netmgr/netmgr.c:775:6
    #19 <null> <null>
    #20 isc__trampoline_run lib/isc/trampoline.c:180:11

  Thread T1 (running) created by main thread at:
    #0 pthread_create <null>
    #1 isc_thread_create lib/isc/thread.c:79:8
    #2 isc__netmgr_create lib/isc/netmgr/netmgr.c:321:3
    #3 isc_managers_create lib/isc/managers.c:39:2
    #4 create_managers bin/named/main.c:935:11
    #5 setup bin/named/main.c:1208:11
    #6 main bin/named/main.c:1500:2

  Thread T2 (running) created by main thread at:
    #0 pthread_create <null>
    #1 isc_thread_create lib/isc/thread.c:79:8
    #2 isc__netmgr_create lib/isc/netmgr/netmgr.c:321:3
    #3 isc_managers_create lib/isc/managers.c:39:2
    #4 create_managers bin/named/main.c:935:11
    #5 setup bin/named/main.c:1208:11
    #6 main bin/named/main.c:1500:2

SUMMARY: ThreadSanitizer: data race in free