--- Begin Message ---
Package: tcc
Version: 0.9.24~cvs20070502-2
Severity: normal
ikiwiki creates suidable wrappers that clear the environment like this:
extern char **environ;
char *newenviron[SIZE];
newenviron[0]=some_string;
environ=newenviron;
exec_wrapped_program();
This works fine with gcc, and AFAIK is legal. With tcc, the code runs,
but the environment seen by the exec'd program remains unchanged.
I've attached an actual ikiwiki wrapper program.
-- System Information:
Debian Release: lenny/sid
APT prefers unstable
APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.22-3-686 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages tcc depends on:
ii libc6 2.6.1-6 GNU C Library: Shared libraries
Versions of packages tcc recommends:
ii libc6-dev [libc-dev] 2.6.1-6 GNU C Library: Development Librari
-- no debconf information
--
see shy jo
/* A wrapper for ikiwiki, can be safely made suid. */
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
extern char **environ;
char *newenviron[8+5];
int i=0;
addenv(char *var, char *val) {
char *s=malloc(strlen(var)+1+strlen(val)+1);
if (!s)
perror("malloc");
sprintf(s, "%s=%s", var, val);
newenviron[i++]=s;
}
int main (int argc, char **argv) {
/* Sanitize environment. */
char *s;
if ((s=getenv("REMOTE_ADDR")))
addenv("REMOTE_ADDR", s);
if ((s=getenv("QUERY_STRING")))
addenv("QUERY_STRING", s);
if ((s=getenv("REQUEST_METHOD")))
addenv("REQUEST_METHOD", s);
if ((s=getenv("REQUEST_URI")))
addenv("REQUEST_URI", s);
if ((s=getenv("CONTENT_TYPE")))
addenv("CONTENT_TYPE", s);
if ((s=getenv("CONTENT_LENGTH")))
addenv("CONTENT_LENGTH", s);
if ((s=getenv("GATEWAY_INTERFACE")))
addenv("GATEWAY_INTERFACE", s);
if ((s=getenv("HTTP_COOKIE")))
addenv("HTTP_COOKIE", s);
if ((s=getenv("REMOTE_USER")))
addenv("REMOTE_USER", s);
newenviron[i++]="HOME=/home/joey";
newenviron[i++]="WRAPPED_OPTIONS=%config = ('verbose' => 0,'svnpath' => 'trunk','adminuser' => ['http://joey.kitenet.net/'],'default_pageext' => 'mdwn','locale' => undef,'underlaydirs' => [],'refresh' => 1,'atom' => 0,'usedirs' => 1,'pingurl' => [],'url' => 'http://kodama.kitenet.net/~joey','render' => undef,'historyurl' => 'http://git.kitenet.net/?p=joey/joeywiki;a=history;f=[[file]]','gitorigin_branch' => '','adminemail' => 'j...@kitenet.net','templatedir' => '/usr/share/ikiwiki/templates','rebuild' => 0,'wiki_file_prune_regexps' => [qr/(?-xism:\\.\\.)/,qr/(?-xism:^\\.)/,qr/(?-xism:\\/\\.)/,qr/(?-xism:\\.x?html?$)/,qr/(?-xism:\\.ikiwiki-new$)/,qr/(?-xism:(^|\\/).svn\\/)/,qr/(?-xism:.arch-ids\\/)/,qr/(?-xism:{arch}\\/)/,qr/(?-xism:(^|\\/)_MTN\\/)/,qr/(?-xism:\\.dpkg-tmp$)/,qr/(?-xism:favicon.ico)/],'wrappers' => 1,'timeformat' => '%a, %d %b %Y %H:%M:%S %z','cgi' => 1,'userdir' => '','wikistatedir' => '/home/joey/src/joeywiki/.ikiwiki','mirrorlist' => {'kite' => 'http://kitenet.net/~joey'},'account_creation_password' => '','libdir' => undef,'diffurl' => 'http://git.kitenet.net/?p=joey/joeywiki;a=blobdiff;h=[[sha1_to]];hp=[[sha1_from]];hb=[[sha1_parent]];f=[[file]]','w3mmode' => 0,'destdir' => '/home/joey/html','wiki_link_regexp' => qr/(?x-ism:\n \\[\\[ # beginning of link\n (?:\n ([^\\]\\|\\n\\s]+) # 1: link text\n \\| # followed by '|'\n )? # optional\n \n ([^\\s\\]#]+) # 2: page to link to\n (?:\n \\# # '#', beginning of anchor\n ([^\\s\\]]+) # 3: anchor text\n )? # optional\n \n \\]\\] # end of link\n )/,'sslcookie' => 0,'svnrepo' => undef,'gitmaster_branch' => 'master','httpauth' => 0,'web_commit_regexp' => qr/(?-xism:^web commit (by (.*?(?=: |$))|from (\\d+\\.\\d+\\.\\d+\\.\\d+)):?(.*))/,'getctime' => 0,'cgiurl' => 'http://kodama.kitenet.net/~joey/ikiwiki.cgi','wiki_file_regexp' => qr/(?-xism:(^[-[:alnum:]_.:\\/+]+$))/,'disable_plugins' => ['passwordauth'],'openidsignup' => 'https://www.myopenid.com/affiliate_signup?affiliate_id=28','underlaydir' => '/usr/share/ikiwiki/basewiki','notify' => 0,'discussion' => 1,'plugin' => ['mdwn','inline','htmlscrubber','passwordauth','openid','signinedit','lockedit','conditional','goodstuff','polygen','fortune','openid','poll','aggregate','html','prettydate','sparkline','postsparkline','teximg','mirrorlist','anonok'],'post_commit' => 0,'wikiname' => 'joey','srcdir' => '/home/joey/src/joeywiki','syslog' => 0,'numbacklinks' => 10,'rss' => 1,'htmlext' => 'html','exclude' => $config{'wiki_file_prune_regexps'}[10],'rcs' => 'git','wrappermode' => '6755');";
newenviron[i]=NULL;
environ=newenviron;
if (setregid(getegid(), -1) != 0 || setreuid(geteuid(), -1) != 0) {
perror("failed to drop real uid/gid");
exit(1);
}
execl("/usr/bin/ikiwiki", "/usr/bin/ikiwiki", NULL);
perror("exec /usr/bin/ikiwiki");
exit(1);
}
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