view src/core/ngx_array.h @ 7566:571383f75a9a

Resolver: fixed possible use-after-free while resolving PTR. Previously, if a response to the PTR request was cached, and ngx_resolver_dup() failed to allocate memory for the resulting name, then the original node was freed but left in expire_queue. A subsequent address resolving would end up in a use-after-free memory access of the node either in ngx_resolver_expire() or ngx_resolver_process_ptr(), when accessing it through expire_queue. The fix is to leave the resolver node intact.
author Sergey Kandaurov <pluknet@nginx.com>
date Tue, 10 Sep 2019 15:42:34 +0300
parents 65b895cd0dfa
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_ARRAY_H_INCLUDED_
#define _NGX_ARRAY_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    void        *elts;
    ngx_uint_t   nelts;
    size_t       size;
    ngx_uint_t   nalloc;
    ngx_pool_t  *pool;
} ngx_array_t;


ngx_array_t *ngx_array_create(ngx_pool_t *p, ngx_uint_t n, size_t size);
void ngx_array_destroy(ngx_array_t *a);
void *ngx_array_push(ngx_array_t *a);
void *ngx_array_push_n(ngx_array_t *a, ngx_uint_t n);


static ngx_inline ngx_int_t
ngx_array_init(ngx_array_t *array, ngx_pool_t *pool, ngx_uint_t n, size_t size)
{
    /*
     * set "array->nelts" before "array->elts", otherwise MSVC thinks
     * that "array->nelts" may be used without having been initialized
     */

    array->nelts = 0;
    array->size = size;
    array->nalloc = n;
    array->pool = pool;

    array->elts = ngx_palloc(pool, n * size);
    if (array->elts == NULL) {
        return NGX_ERROR;
    }

    return NGX_OK;
}


#endif /* _NGX_ARRAY_H_INCLUDED_ */