Mercurial > hg > nginx
view auto/configure @ 6351:497d0cff8ace
Resolver: fixed use-after-free memory accesses with CNAME.
When several requests were waiting for a response, then after getting
a CNAME response only the last request's context had the name updated.
Contexts of other requests had the wrong name. This name was used by
ngx_resolve_name_done() to find the node to remove the request context
from. When the name was wrong, the request could not be properly
cancelled, its context was freed but stayed linked to the node's waiting
list. This happened e.g. when the first request was aborted or timed
out before the resolving completed. When it completed, this triggered
a use-after-free memory access by calling ctx->handler of already freed
request context. The bug manifests itself by
"could not cancel <name> resolving" alerts in error_log.
When a request was responded with a CNAME, the request context kept
the pointer to the original node's rn->u.cname. If the original node
expired before the resolving timed out or completed with an error,
this would trigger a use-after-free memory access via ctx->name in
ctx->handler().
The fix is to keep ctx->name unmodified. The name from context
is no longer used by ngx_resolve_name_done(). Instead, we now keep
the pointer to resolver node to which this request is linked.
Keeping the original name intact also improves logging.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 26 Jan 2016 16:46:59 +0300 |
parents | e69d5e9be292 |
children | 4a343228c55e |
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#!/bin/sh # Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. LC_ALL=C export LC_ALL . auto/options . auto/init . auto/sources test -d $NGX_OBJS || mkdir -p $NGX_OBJS echo > $NGX_AUTO_HEADERS_H echo > $NGX_AUTOCONF_ERR echo "#define NGX_CONFIGURE \"$NGX_CONFIGURE\"" > $NGX_AUTO_CONFIG_H if [ $NGX_DEBUG = YES ]; then have=NGX_DEBUG . auto/have fi if test -z "$NGX_PLATFORM"; then echo "checking for OS" NGX_SYSTEM=`uname -s 2>/dev/null` NGX_RELEASE=`uname -r 2>/dev/null` NGX_MACHINE=`uname -m 2>/dev/null` echo " + $NGX_SYSTEM $NGX_RELEASE $NGX_MACHINE" NGX_PLATFORM="$NGX_SYSTEM:$NGX_RELEASE:$NGX_MACHINE"; case "$NGX_SYSTEM" in MINGW32_*) NGX_PLATFORM=win32 ;; esac else echo "building for $NGX_PLATFORM" NGX_SYSTEM=$NGX_PLATFORM fi . auto/cc/conf if [ "$NGX_PLATFORM" != win32 ]; then . auto/headers fi . auto/os/conf if [ "$NGX_PLATFORM" != win32 ]; then . auto/unix fi . auto/threads . auto/modules . auto/lib/conf case ".$NGX_PREFIX" in .) NGX_PREFIX=${NGX_PREFIX:-/usr/local/nginx} have=NGX_PREFIX value="\"$NGX_PREFIX/\"" . auto/define ;; .!) NGX_PREFIX= ;; *) have=NGX_PREFIX value="\"$NGX_PREFIX/\"" . auto/define ;; esac if [ ".$NGX_CONF_PREFIX" != "." ]; then have=NGX_CONF_PREFIX value="\"$NGX_CONF_PREFIX/\"" . auto/define fi have=NGX_SBIN_PATH value="\"$NGX_SBIN_PATH\"" . auto/define have=NGX_CONF_PATH value="\"$NGX_CONF_PATH\"" . auto/define have=NGX_PID_PATH value="\"$NGX_PID_PATH\"" . auto/define have=NGX_LOCK_PATH value="\"$NGX_LOCK_PATH\"" . auto/define have=NGX_ERROR_LOG_PATH value="\"$NGX_ERROR_LOG_PATH\"" . auto/define have=NGX_HTTP_LOG_PATH value="\"$NGX_HTTP_LOG_PATH\"" . auto/define have=NGX_HTTP_CLIENT_TEMP_PATH value="\"$NGX_HTTP_CLIENT_TEMP_PATH\"" . auto/define have=NGX_HTTP_PROXY_TEMP_PATH value="\"$NGX_HTTP_PROXY_TEMP_PATH\"" . auto/define have=NGX_HTTP_FASTCGI_TEMP_PATH value="\"$NGX_HTTP_FASTCGI_TEMP_PATH\"" . auto/define have=NGX_HTTP_UWSGI_TEMP_PATH value="\"$NGX_HTTP_UWSGI_TEMP_PATH\"" . auto/define have=NGX_HTTP_SCGI_TEMP_PATH value="\"$NGX_HTTP_SCGI_TEMP_PATH\"" . auto/define . auto/make . auto/lib/make . auto/install # STUB . auto/stubs have=NGX_USER value="\"$NGX_USER\"" . auto/define have=NGX_GROUP value="\"$NGX_GROUP\"" . auto/define if [ ".$NGX_BUILD" != "." ]; then have=NGX_BUILD value="\"$NGX_BUILD\"" . auto/define fi . auto/summary