view auto/os/linux @ 7674:7731c710796f

Memcached: protect from too long responses. If a memcached response was followed by a correct trailer, and then the NUL character followed by some extra data - this was accepted by the trailer checking code. This in turn resulted in ctx->rest underflow and caused negative size buffer on the next reading from the upstream, followed by the "negative size buf in writer" alert. Fix is to always check for too long responses, so a correct trailer cannot be followed by extra data.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 06 Jul 2020 18:36:17 +0300
parents f7e79596baf2
children e2e9e0fae747 d3747ba486e7
line wrap: on
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


have=NGX_LINUX . auto/have_headers

CORE_INCS="$UNIX_INCS"
CORE_DEPS="$UNIX_DEPS $LINUX_DEPS"
CORE_SRCS="$UNIX_SRCS $LINUX_SRCS"

ngx_spacer='
'

cc_aux_flags="$CC_AUX_FLAGS"
CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"


# Linux kernel version

version=$((`uname -r \
    | sed -n -e 's/^\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/ \
                                                 \1*256*256+\2*256+\3/p' \
             -e 's/^\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/\1*256*256+\2*256/p'`))

version=${version:-0}


# posix_fadvise64() had been implemented in 2.5.60

if [ $version -lt 132412 ]; then
    have=NGX_HAVE_POSIX_FADVISE . auto/nohave
fi

# epoll, EPOLLET version

ngx_feature="epoll"
ngx_feature_name="NGX_HAVE_EPOLL"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/epoll.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int efd = 0;
                  struct epoll_event ee;
                  ee.events = EPOLLIN|EPOLLOUT|EPOLLET;
                  ee.data.ptr = NULL;
                  (void) ee;
                  efd = epoll_create(100);
                  if (efd == -1) return 1;"
. auto/feature

if [ $ngx_found = yes ]; then
    have=NGX_HAVE_CLEAR_EVENT . auto/have
    CORE_SRCS="$CORE_SRCS $EPOLL_SRCS"
    EVENT_MODULES="$EVENT_MODULES $EPOLL_MODULE"
    EVENT_FOUND=YES


    # EPOLLRDHUP appeared in Linux 2.6.17, glibc 2.8

    ngx_feature="EPOLLRDHUP"
    ngx_feature_name="NGX_HAVE_EPOLLRDHUP"
    ngx_feature_run=no
    ngx_feature_incs="#include <sys/epoll.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="int efd = 0, fd = 0;
                      struct epoll_event ee;
                      ee.events = EPOLLIN|EPOLLRDHUP|EPOLLET;
                      ee.data.ptr = NULL;
                      epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)"
    . auto/feature


    # EPOLLEXCLUSIVE appeared in Linux 4.5, glibc 2.24

    ngx_feature="EPOLLEXCLUSIVE"
    ngx_feature_name="NGX_HAVE_EPOLLEXCLUSIVE"
    ngx_feature_run=no
    ngx_feature_incs="#include <sys/epoll.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="int efd = 0, fd = 0;
                      struct epoll_event ee;
                      ee.events = EPOLLIN|EPOLLEXCLUSIVE;
                      ee.data.ptr = NULL;
                      epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)"
    . auto/feature
fi


# O_PATH and AT_EMPTY_PATH were introduced in 2.6.39, glibc 2.14

ngx_feature="O_PATH"
ngx_feature_name="NGX_HAVE_O_PATH"
ngx_feature_run=no
ngx_feature_incs="#include <sys/types.h>
                  #include <sys/stat.h>
                  #include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int fd; struct stat sb;
                  fd = openat(AT_FDCWD, \".\", O_PATH|O_DIRECTORY|O_NOFOLLOW);
                  if (fstatat(fd, \"\", &sb, AT_EMPTY_PATH) != 0) return 1"
. auto/feature


# sendfile()

CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE"
ngx_feature="sendfile()"
ngx_feature_name="NGX_HAVE_SENDFILE"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/sendfile.h>
                  #include <errno.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int s = 0, fd = 1;
                  ssize_t n; off_t off = 0;
                  n = sendfile(s, fd, &off, 1);
                  if (n == -1 && errno == ENOSYS) return 1"
. auto/feature

if [ $ngx_found = yes ]; then
    CORE_SRCS="$CORE_SRCS $LINUX_SENDFILE_SRCS"
fi


# sendfile64()

CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"
ngx_feature="sendfile64()"
ngx_feature_name="NGX_HAVE_SENDFILE64"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/sendfile.h>
                  #include <errno.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int s = 0, fd = 1;
                  ssize_t n; off_t off = 0;
                  n = sendfile(s, fd, &off, 1);
                  if (n == -1 && errno == ENOSYS) return 1"
. auto/feature


ngx_include="sys/prctl.h"; . auto/include

# prctl(PR_SET_DUMPABLE)

ngx_feature="prctl(PR_SET_DUMPABLE)"
ngx_feature_name="NGX_HAVE_PR_SET_DUMPABLE"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/prctl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1) return 1"
. auto/feature


# prctl(PR_SET_KEEPCAPS)

ngx_feature="prctl(PR_SET_KEEPCAPS)"
ngx_feature_name="NGX_HAVE_PR_SET_KEEPCAPS"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/prctl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) return 1"
. auto/feature


# capabilities

ngx_feature="capabilities"
ngx_feature_name="NGX_HAVE_CAPABILITIES"
ngx_feature_run=no
ngx_feature_incs="#include <linux/capability.h>
                  #include <sys/syscall.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct __user_cap_data_struct    data;
                  struct __user_cap_header_struct  header;

                  header.version = _LINUX_CAPABILITY_VERSION_1;
                  data.effective = CAP_TO_MASK(CAP_NET_RAW);
                  data.permitted = 0;

                  (void) header;
                  (void) data;
                  (void) SYS_capset"
. auto/feature


# crypt_r()

ngx_feature="crypt_r()"
ngx_feature_name="NGX_HAVE_GNU_CRYPT_R"
ngx_feature_run=no
ngx_feature_incs="#include <crypt.h>"
ngx_feature_path=
ngx_feature_libs=-lcrypt
ngx_feature_test="struct crypt_data  cd;
                  crypt_r(\"key\", \"salt\", &cd);"
. auto/feature


ngx_include="sys/vfs.h";     . auto/include


CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"