Mercurial > hg > nginx
view src/os/unix/ngx_alloc.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 | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> ngx_uint_t ngx_pagesize; ngx_uint_t ngx_pagesize_shift; ngx_uint_t ngx_cacheline_size; void * ngx_alloc(size_t size, ngx_log_t *log) { void *p; p = malloc(size); if (p == NULL) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "malloc(%uz) failed", size); } ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, log, 0, "malloc: %p:%uz", p, size); return p; } void * ngx_calloc(size_t size, ngx_log_t *log) { void *p; p = ngx_alloc(size, log); if (p) { ngx_memzero(p, size); } return p; } #if (NGX_HAVE_POSIX_MEMALIGN) void * ngx_memalign(size_t alignment, size_t size, ngx_log_t *log) { void *p; int err; err = posix_memalign(&p, alignment, size); if (err) { ngx_log_error(NGX_LOG_EMERG, log, err, "posix_memalign(%uz, %uz) failed", alignment, size); p = NULL; } ngx_log_debug3(NGX_LOG_DEBUG_ALLOC, log, 0, "posix_memalign: %p:%uz @%uz", p, size, alignment); return p; } #elif (NGX_HAVE_MEMALIGN) void * ngx_memalign(size_t alignment, size_t size, ngx_log_t *log) { void *p; p = memalign(alignment, size); if (p == NULL) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "memalign(%uz, %uz) failed", alignment, size); } ngx_log_debug3(NGX_LOG_DEBUG_ALLOC, log, 0, "memalign: %p:%uz @%uz", p, size, alignment); return p; } #endif