Mercurial > hg > nginx
view src/os/unix/ngx_sunpro_atomic_sparc64.h @ 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. */ #if (NGX_PTR_SIZE == 4) #define NGX_CASA ngx_casa #else #define NGX_CASA ngx_casxa #endif ngx_atomic_uint_t ngx_casa(ngx_atomic_uint_t set, ngx_atomic_uint_t old, ngx_atomic_t *lock); ngx_atomic_uint_t ngx_casxa(ngx_atomic_uint_t set, ngx_atomic_uint_t old, ngx_atomic_t *lock); /* the code in src/os/unix/ngx_sunpro_sparc64.il */ static ngx_inline ngx_atomic_uint_t ngx_atomic_cmp_set(ngx_atomic_t *lock, ngx_atomic_uint_t old, ngx_atomic_uint_t set) { set = NGX_CASA(set, old, lock); return (set == old); } static ngx_inline ngx_atomic_int_t ngx_atomic_fetch_add(ngx_atomic_t *value, ngx_atomic_int_t add) { ngx_atomic_uint_t old, res; old = *value; for ( ;; ) { res = old + add; res = NGX_CASA(res, old, value); if (res == old) { return res; } old = res; } } #define ngx_memory_barrier() \ __asm (".volatile"); \ __asm ("membar #LoadLoad | #LoadStore | #StoreStore | #StoreLoad"); \ __asm (".nonvolatile") #define ngx_cpu_pause()