Mercurial > hg > nginx

view auto/os/freebsd @ 6359:dac6eda40475 stable-1.8

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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 83d54192e97b
children 4dc8e7b62216
line wrap: on
line source


# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


have=NGX_FREEBSD . auto/have_headers

CORE_INCS="$UNIX_INCS"
CORE_DEPS="$UNIX_DEPS $FREEBSD_DEPS"
CORE_SRCS="$UNIX_SRCS $FREEBSD_SRCS"

ngx_spacer='
'


# __FreeBSD_version and sysctl kern.osreldate are the best ways
# to determine whether some capability exists and is safe to use.
# __FreeBSD_version is used for the testing of the build environment.
# sysctl kern.osreldate is used for the testing of the kernel capabilities.

version=`grep "#define __FreeBSD_version" /usr/include/osreldate.h \
         | sed -e 's/^.* \(.*\)$/\1/'`

osreldate=`/sbin/sysctl -n kern.osreldate`


# setproctitle() in libutil

if [ \( $version -ge 500000 -a $version -lt 500012 \) \
     -o $version -lt 410002 ]
then
    echo " + setproctitle() in libutil"

    CORE_LIBS="$CORE_LIBS -lutil"
    NGX_SETPROCTITLE_LIB="-lutil"
fi

# sendfile

if [ $osreldate -gt 300007 ]; then
    echo " + sendfile() found"

    have=NGX_HAVE_SENDFILE . auto/have
    CORE_SRCS="$CORE_SRCS $FREEBSD_SENDFILE_SRCS"
fi

if [ $NGX_FILE_AIO = YES ]; then
    if [ $osreldate -gt 502103 ]; then
        echo " + sendfile()'s SF_NODISKIO found"

        have=NGX_HAVE_AIO_SENDFILE . auto/have
    fi
fi

# POSIX semaphores
# http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/127545

if [ $osreldate -ge 701106 ]; then
    echo " + POSIX semaphores should work"
else
    have=NGX_HAVE_POSIX_SEM . auto/nohave
fi


# kqueue

if [ \( $osreldate -lt 500000 -a $osreldate -ge 410000 \) \
     -o $osreldate -ge 500011 ]
then
    echo " + kqueue found"

    have=NGX_HAVE_KQUEUE . auto/have
    have=NGX_HAVE_CLEAR_EVENT . auto/have
    EVENT_MODULES="$EVENT_MODULES $KQUEUE_MODULE"
    CORE_SRCS="$CORE_SRCS $KQUEUE_SRCS"
    EVENT_FOUND=YES
fi


NGX_KQUEUE_CHECKED=YES


# kqueue's NOTE_LOWAT

if [ \( $version -lt 500000 -a $version -ge 430000 \) \
     -o $version -ge 500018 ]
then
    echo " + kqueue's NOTE_LOWAT found"
    have=NGX_HAVE_LOWAT_EVENT . auto/have
fi

# kqueue's EVFILT_TIMER

if [ \( $version -lt 500000 -a $version -ge 440001 \) \
     -o $version -ge 500023 ]
then
    echo " + kqueue's EVFILT_TIMER found"
    have=NGX_HAVE_TIMER_EVENT . auto/have
fi


if [ $EVENT_AIO = YES ]; then
    if [ \( $version -lt 500000 -a $version -ge 430000 \) \
         -o $version -ge 500014 ]
    then
        have=NGX_HAVE_AIO . auto/have
        EVENT_MODULES="$EVENT_MODULES $AIO_MODULE"
        CORE_SRCS="$CORE_SRCS $AIO_SRCS"
    else

cat << END

$0: error: the kqueue does not support AIO on this FreeBSD version

END

        exit 1
    fi
fi


# cpuset_setaffinity()

if [ $version -ge 701000 ]; then
    echo " + cpuset_setaffinity() found"
    have=NGX_HAVE_CPUSET_SETAFFINITY . auto/have
fi