Mercurial > hg > nginx
view src/core/ngx_list.c @ 7048:80224192163c
Resolver: fixed possible use-after-free while resolving SRV.
Resolving an SRV record includes resolving its host names in subrequests.
Previously, if memory allocation failed while reporting a subrequest result
after receiving a response from a DNS server, the SRV resolve handler was
called immediately with the NGX_ERROR state. However, if the SRV record
included another copy of the resolved name, it was reported once again.
This could trigger the use-after-free memory access after SRV resolve
handler freed the resolve context by calling ngx_resolve_name_done().
Now the SRV resolve handler is called only when all its subrequests are
completed.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 04 Jul 2017 18:07:29 +0300 |
parents | a82f305487c2 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> ngx_list_t * ngx_list_create(ngx_pool_t *pool, ngx_uint_t n, size_t size) { ngx_list_t *list; list = ngx_palloc(pool, sizeof(ngx_list_t)); if (list == NULL) { return NULL; } if (ngx_list_init(list, pool, n, size) != NGX_OK) { return NULL; } return list; } void * ngx_list_push(ngx_list_t *l) { void *elt; ngx_list_part_t *last; last = l->last; if (last->nelts == l->nalloc) { /* the last part is full, allocate a new list part */ last = ngx_palloc(l->pool, sizeof(ngx_list_part_t)); if (last == NULL) { return NULL; } last->elts = ngx_palloc(l->pool, l->nalloc * l->size); if (last->elts == NULL) { return NULL; } last->nelts = 0; last->next = NULL; l->last->next = last; l->last = last; } elt = (char *) last->elts + l->size * last->nelts; last->nelts++; return elt; }