From 80bf3f38525a8fddca2bbc61d8fe228475cc7c1e Mon Sep 17 00:00:00 2001 From: Mark Andrews Date: Wed, 26 Aug 2020 16:24:13 +1000 Subject: [PATCH] Only test node->data if we care about whether data is present or not. WARNING: ThreadSanitizer: data race (pid=28788) Write of size 8 at 0x7b200002e060 by thread T1 (mutexes: write M2947): #0 add32 /builds/isc-projects/bind9/lib/dns/rbtdb.c:6638:18 (libdns.so.1110+0xe7843) #1 addrdataset /builds/isc-projects/bind9/lib/dns/rbtdb.c:6975:12 (libdns.so.1110+0xe4185) #2 dns_db_addrdataset /builds/isc-projects/bind9/lib/dns/db.c:783:10 (libdns.so.1110+0x650ee) #3 validated /builds/isc-projects/bind9/lib/dns/resolver.c:5140:11 (libdns.so.1110+0x1909f7) #4 dispatch /builds/isc-projects/bind9/lib/isc/task.c:1157:7 (libisc.so.1107+0x507f5) #5 run /builds/isc-projects/bind9/lib/isc/task.c:1331:2 (libisc.so.1107+0x4d749) Previous read of size 8 at 0x7b200002e060 by thread T5 (mutexes: write M521146194917735760): #0 dns_rbt_findnode /builds/isc-projects/bind9/lib/dns/rbt.c:1708:9 (libdns.so.1110+0xd910d) #1 cache_find /builds/isc-projects/bind9/lib/dns/rbtdb.c:5098:11 (libdns.so.1110+0xe188e) #2 dns_db_find /builds/isc-projects/bind9/lib/dns/db.c:554:11 (libdns.so.1110+0x642bb) #3 dns_view_find2 /builds/isc-projects/bind9/lib/dns/view.c:1068:11 (libdns.so.1110+0x1cc2c4) #4 dbfind_name /builds/isc-projects/bind9/lib/dns/adb.c:3714:11 (libdns.so.1110+0x46a4b) #5 dns_adb_createfind2 /builds/isc-projects/bind9/lib/dns/adb.c:3133:12 (libdns.so.1110+0x45278) #6 findname /builds/isc-projects/bind9/lib/dns/resolver.c:3166:11 (libdns.so.1110+0x1827f0) #7 fctx_getaddresses /builds/isc-projects/bind9/lib/dns/resolver.c:3462:3 (libdns.so.1110+0x18032d) #8 fctx_try /builds/isc-projects/bind9/lib/dns/resolver.c:3819:12 (libdns.so.1110+0x17e174) #9 fctx_start /builds/isc-projects/bind9/lib/dns/resolver.c:4219:4 (libdns.so.1110+0x1787a3) #10 dispatch /builds/isc-projects/bind9/lib/isc/task.c:1157:7 (libisc.so.1107+0x507f5) #11 run /builds/isc-projects/bind9/lib/isc/task.c:1331:2 (libisc.so.1107+0x4d749) Conflict: NA Reference: https://gitlab.isc.org/isc-projects/bind9/-/commit/80bf3f38525a8fddca2bbc61d8fe228475cc7c1e --- lib/dns/rbt.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/lib/dns/rbt.c b/lib/dns/rbt.c index 04cf306220..d886d5bbbf 100644 --- a/lib/dns/rbt.c +++ b/lib/dns/rbt.c @@ -218,6 +218,9 @@ getdata(dns_rbtnode_t *node, file_header_t *header) { #define IS_ROOT(node) ((node)->is_root == 1) #define FINDCALLBACK(node) ((node)->find_callback == 1) +#define WANTEMPTYDATA_OR_DATA(options, node) \ + ((options & DNS_RBTFIND_EMPTYDATA) != 0 || DATA(node) != NULL) + /*% * Structure elements from the rbtdb.c, not * used as part of the rbt.c algorithms. @@ -1705,9 +1708,9 @@ dns_rbt_findnode(dns_rbt_t *rbt, const dns_name_t *name, dns_name_t *foundname, /* * This might be the closest enclosing name. */ - if (DATA(current) != NULL || - (options & DNS_RBTFIND_EMPTYDATA) != 0) + if (WANTEMPTYDATA_OR_DATA(options, current)) { *node = current; + } /* * Point the chain to the next level. This @@ -1778,8 +1781,7 @@ dns_rbt_findnode(dns_rbt_t *rbt, const dns_name_t *name, dns_name_t *foundname, * ISC_R_SUCCESS to indicate an exact match. */ if (current != NULL && (options & DNS_RBTFIND_NOEXACT) == 0 && - (DATA(current) != NULL || - (options & DNS_RBTFIND_EMPTYDATA) != 0)) { + (WANTEMPTYDATA_OR_DATA(options, current))) { /* * Found an exact match. */ @@ -2016,11 +2018,11 @@ dns_rbt_findname(dns_rbt_t *rbt, const dns_name_t *name, unsigned int options, result = dns_rbt_findnode(rbt, name, foundname, &node, NULL, options, NULL, NULL); - if (node != NULL && - (DATA(node) != NULL || (options & DNS_RBTFIND_EMPTYDATA) != 0)) + if (node != NULL && WANTEMPTYDATA_OR_DATA(options, node)) { *data = DATA(node); - else + } else { result = ISC_R_NOTFOUND; + } return (result); } @@ -2857,9 +2859,10 @@ deletetreeflat(dns_rbt_t *rbt, unsigned int quantum, bool unhash, dns_rbtnode_t *node = root; root = PARENT(root); - if (DATA(node) != NULL && rbt->data_deleter != NULL) + if (rbt->data_deleter != NULL && DATA(node) != NULL) { rbt->data_deleter(DATA(node), rbt->deleter_arg); + } if (unhash) unhash_node(rbt, node); /* -- 2.23.0