view auto/lib/zlib/conf @ 6359:dac6eda40475 stable-1.8

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 66d001c5378c
children 78f8ac479735
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


if [ $ZLIB != NONE ]; then
    CORE_INCS="$CORE_INCS $ZLIB"

    case "$NGX_CC_NAME" in

        msvc* | owc* | bcc)
            have=NGX_ZLIB . auto/have
            LINK_DEPS="$LINK_DEPS $ZLIB/zlib.lib"
            CORE_LIBS="$CORE_LIBS $ZLIB/zlib.lib"
        ;;

        icc*)
            have=NGX_ZLIB . auto/have
            LINK_DEPS="$LINK_DEPS $ZLIB/libz.a"

            # to allow -ipo optimization we link with the *.o but not library
            CORE_LIBS="$CORE_LIBS $ZLIB/adler32.o"
            CORE_LIBS="$CORE_LIBS $ZLIB/crc32.o"
            CORE_LIBS="$CORE_LIBS $ZLIB/deflate.o"
            CORE_LIBS="$CORE_LIBS $ZLIB/trees.o"
            CORE_LIBS="$CORE_LIBS $ZLIB/zutil.o"
            CORE_LIBS="$CORE_LIBS $ZLIB/compress.o"

            if [ $ZLIB_ASM != NO ]; then
                CORE_LIBS="$CORE_LIBS $ZLIB/match.o"
            fi
        ;;

        *)
            have=NGX_ZLIB . auto/have
            LINK_DEPS="$LINK_DEPS $ZLIB/libz.a"
            CORE_LIBS="$CORE_LIBS $ZLIB/libz.a"
            #CORE_LIBS="$CORE_LIBS -L $ZLIB -lz"
        ;;

    esac

else

    if [ "$NGX_PLATFORM" != win32 ]; then
        ZLIB=NO

        # FreeBSD, Solaris, Linux

        ngx_feature="zlib library"
        ngx_feature_name="NGX_ZLIB"
        ngx_feature_run=no
        ngx_feature_incs="#include <zlib.h>"
        ngx_feature_path=
        ngx_feature_libs="-lz"
        ngx_feature_test="z_stream z; deflate(&z, Z_NO_FLUSH)"
        . auto/feature


        if [ $ngx_found = yes ]; then
            CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
            ZLIB=YES
            ngx_found=no
        fi
    fi

    if [ $ZLIB != YES ]; then
cat << END

$0: error: the HTTP gzip module requires the zlib library.
You can either disable the module by using --without-http_gzip_module
option, or install the zlib library into the system, or build the zlib library
statically from the source with nginx by using --with-zlib=<path> option.

END
        exit 1
    fi

fi