Mercurial > hg > nginx
comparison src/core/ngx_resolver.c @ 4619:3171ec7d0d05
Resolver: protection from duplicate responses.
If we already had CNAME in resolver node (i.e. rn->cnlen and rn->u.cname
set), and got additional response with A record, it resulted in rn->cnlen
set and rn->u.cname overwritten by rn->u.addr (or rn->u.addrs), causing
segmentation fault later in ngx_resolver_free_node() on an attempt to free
overwritten rn->u.cname. The opposite (i.e. CNAME got after A) might cause
similar problems as well.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 14 May 2012 09:13:45 +0000 |
parents | 778d2cc03e22 |
children | bc5f881323b8 |
comparison
equal
deleted
inserted
replaced
4618:c05cfc46b3bc | 4619:3171ec7d0d05 |
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511 | 511 |
512 ngx_queue_remove(&rn->queue); | 512 ngx_queue_remove(&rn->queue); |
513 | 513 |
514 /* lock alloc mutex */ | 514 /* lock alloc mutex */ |
515 | 515 |
516 ngx_resolver_free_locked(r, rn->query); | 516 if (rn->query) { |
517 rn->query = NULL; | 517 ngx_resolver_free_locked(r, rn->query); |
518 rn->query = NULL; | |
519 } | |
518 | 520 |
519 if (rn->cnlen) { | 521 if (rn->cnlen) { |
520 ngx_resolver_free_locked(r, rn->u.cname); | 522 ngx_resolver_free_locked(r, rn->u.cname); |
521 } | 523 } |
522 | 524 |
1407 | 1409 |
1408 if (naddrs > 1) { | 1410 if (naddrs > 1) { |
1409 ngx_resolver_free(r, addrs); | 1411 ngx_resolver_free(r, addrs); |
1410 } | 1412 } |
1411 | 1413 |
1414 ngx_resolver_free(r, rn->query); | |
1415 rn->query = NULL; | |
1416 | |
1412 return; | 1417 return; |
1413 | 1418 |
1414 } else if (cname) { | 1419 } else if (cname) { |
1415 | 1420 |
1416 /* CNAME only */ | 1421 /* CNAME only */ |
1438 if (ctx) { | 1443 if (ctx) { |
1439 ctx->name = name; | 1444 ctx->name = name; |
1440 | 1445 |
1441 (void) ngx_resolve_name_locked(r, ctx); | 1446 (void) ngx_resolve_name_locked(r, ctx); |
1442 } | 1447 } |
1448 | |
1449 ngx_resolver_free(r, rn->query); | |
1450 rn->query = NULL; | |
1443 | 1451 |
1444 return; | 1452 return; |
1445 } | 1453 } |
1446 | 1454 |
1447 ngx_log_error(r->log_level, r->log, 0, | 1455 ngx_log_error(r->log_level, r->log, 0, |