Data race lib/dns/adb.c:1537 in clean_finds_at_name

Job respdiff-long:tsan failed for d2fbe443b833d093f68bf4f5a1736242fc8d18a1 (v9.18-S).

WARNING: ThreadSanitizer: data race 
  Write of size 4 at 0x000000000001 by thread T1 (mutexes: write M1, write M2):
    #0 clean_finds_at_name lib/dns/adb.c:1537
    #1 fetch_callback lib/dns/adb.c:4009
    #2 task_run lib/isc/task.c:815
    #3 isc_task_run lib/isc/task.c:896
    #4 isc__nm_async_task netmgr/netmgr.c:848
    #5 process_netievent netmgr/netmgr.c:920
    #6 process_queue netmgr/netmgr.c:1013
    #7 process_all_queues netmgr/netmgr.c:767
    #8 async_cb netmgr/netmgr.c:796
    #9 uv__async_io /usr/src/libuv-v1.44.1/src/unix/async.c:163
    #10 isc__trampoline_run lib/isc/trampoline.c:189

  Previous read of size 4 at 0x000000000001 by thread T2:
    #0 findname lib/dns/resolver.c:3749
    #1 fctx_getaddresses lib/dns/resolver.c:3993
    #2 fctx_try lib/dns/resolver.c:4390
    #3 rctx_nextserver lib/dns/resolver.c:10356
    #4 rctx_done lib/dns/resolver.c:10503
    #5 resquery_response lib/dns/resolver.c:8511
    #6 udp_recv lib/dns/dispatch.c:638
    #7 isc__nm_async_readcb netmgr/netmgr.c:2885
    #8 isc__nm_readcb netmgr/netmgr.c:2858
    #9 udp_recv_cb netmgr/udp.c:650
    #10 isc__nm_udp_read_cb netmgr/udp.c:1057
    #11 uv__udp_recvmsg /usr/src/libuv-v1.44.1/src/unix/udp.c:303
    #12 isc__trampoline_run lib/isc/trampoline.c:189

  Location is heap block of size 256 at 0x000000000025 allocated by thread T2:
    #0 malloc ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:651
    #1 mallocx lib/isc/jemalloc_shim.h:35
    #2 mem_get lib/isc/mem.c:343
    #3 isc__mem_get lib/isc/mem.c:761
    #4 new_adbfind lib/dns/adb.c:1901
    #5 dns_adb_createfind lib/dns/adb.c:2934
    #6 findname lib/dns/resolver.c:3656
    #7 fctx_getaddresses lib/dns/resolver.c:3993
    #8 fctx_try lib/dns/resolver.c:4390
    #9 rctx_nextserver lib/dns/resolver.c:10356
    #10 rctx_done lib/dns/resolver.c:10503
    #11 resquery_response lib/dns/resolver.c:8511
    #12 udp_recv lib/dns/dispatch.c:638
    #13 isc__nm_async_readcb netmgr/netmgr.c:2885
    #14 isc__nm_readcb netmgr/netmgr.c:2858
    #15 udp_recv_cb netmgr/udp.c:650
    #16 isc__nm_udp_read_cb netmgr/udp.c:1057
    #17 uv__udp_recvmsg /usr/src/libuv-v1.44.1/src/unix/udp.c:303
    #18 isc__trampoline_run lib/isc/trampoline.c:189

  Mutex M1 is already destroyed.

  Mutex M2 is already destroyed.

  Thread T1 (running) created by main thread at:
    #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:962
    #1 isc_thread_create lib/isc/thread.c:73
    #2 isc__netmgr_create netmgr/netmgr.c:311
    #3 isc_managers_create lib/isc/managers.c:31
    #4 create_managers bin/named/main.c:1042
    #5 setup bin/named/main.c:1313
    #6 main bin/named/main.c:1594

  Thread T2 (running) created by main thread at:
    #0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:962
    #1 isc_thread_create lib/isc/thread.c:73
    #2 isc__netmgr_create netmgr/netmgr.c:311
    #3 isc_managers_create lib/isc/managers.c:31
    #4 create_managers bin/named/main.c:1042
    #5 setup bin/named/main.c:1313
    #6 main bin/named/main.c:1594

SUMMARY: ThreadSanitizer: data race lib/dns/adb.c:1537 in clean_finds_at_name