From 84ae282f938068fa5c09f7c157ea0086b2ab760b Mon Sep 17 00:00:00 2001 From: Ruslan Ermilov Date: Tue, 26 Jan 2016 16:46:31 +0300 Subject: Resolver: fixed crashes in timeout handler. If one or more requests were waiting for a response, then after getting a CNAME response, the timeout event on the first request remained active, pointing to the wrong node with an empty rn->waiting list, and that could cause either null pointer dereference or use-after-free memory access if this timeout expired. If several requests were waiting for a response, and the first request terminated (e.g., due to client closing a connection), other requests were left without a timeout and could potentially wait indefinitely. This is fixed by introducing per-request independent timeouts. This change also reverts 954867a2f0a6 and 5004210e8c78. --- src/core/ngx_resolver.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'src/core/ngx_resolver.h') diff --git a/src/core/ngx_resolver.h b/src/core/ngx_resolver.h index d3519fb6f..22f249595 100644 --- a/src/core/ngx_resolver.h +++ b/src/core/ngx_resolver.h @@ -51,15 +51,11 @@ typedef void (*ngx_resolver_handler_pt)(ngx_resolver_ctx_t *ctx); typedef struct { - /* PTR: resolved name, A: name to resolve */ - u_char *name; - + ngx_rbtree_node_t node; ngx_queue_t queue; - /* event ident must be after 3 pointers as in ngx_connection_t */ - ngx_int_t ident; - - ngx_rbtree_node_t node; + /* PTR: resolved name, A: name to resolve */ + u_char *name; #if (NGX_HAVE_INET6) /* PTR: IPv6 address to resolve (IPv4 address is in rbtree node key) */ @@ -147,6 +143,9 @@ struct ngx_resolver_ctx_s { ngx_resolver_t *resolver; ngx_udp_connection_t *udp_connection; + /* event ident must be after 3 pointers as in ngx_connection_t */ + ngx_int_t ident; + ngx_int_t state; ngx_str_t name; -- cgit