Req #38915 [PATCH]: Apache: system() (and similar) don't cleanup opened handles of Apache

Edit report at https://bugs.php.net/bug.php?id=38915&edit=1 ID: 38915 Patch added by: testing@example.com Reported by: dimmoborgir at gmail dot com Summary: Apache: system() (and similar) don't cleanup opened handles of Apache Status: Analyzed Type: Feature/Change Request Package: Program Execution Operating System: UNIX PHP Version: 5.2.2, 4.4.7 Block user comment: N Private report: N New Comment: The following patch has been added/updated: Patch Name: tsSLAueP Revision: 1703689855 URL: https://bugs.php.net/patch-display.php?bug=38915&patch=tsSLAueP&revision=1703689855 Previous Comments: ------------------------------------------------------------------------ [2014-03-14 13:02:42] php at braten dot be Related To: Bug #15529 ------------------------------------------------------------------------ [2013-12-03 17:23:11] brak at gameservers dot com This same issue appears to happen with PHP-FPM (I am using nginx as the webserver, but that shouldn't matter). PHP version 5.4.22 on Linux (CentOS 6.5) Quick example: <?php $p = popen('/bin/bash -c "sleep 60"','w'); pclose($p); ?> Now find the child process (ps aux | grep sleep) and lsof -p XXX -n: sleep 13443 nobody 0r FIFO 0,8 0t0 10237775 pipe sleep 13443 nobody 1u CHR 1,3 0t0 3920 /dev/null sleep 13443 nobody 2u CHR 1,3 0t0 3920 /dev/null sleep 13443 nobody 4u IPv4 10236693 0t0 TCP 127.0.0.1:cslistener->127.0.0.1:53151 (ESTABLISHED) sleep 13443 nobody 9u REG 0,9 0 3918 [eventpoll] FD 4 there is the TCP connection from the PHP worker process to the web server. ------------------------------------------------------------------------ [2012-10-31 23:56:34] oliver at realtsp dot com we solved by passing the forked/exec'd process through a bash shell and closing all te file descriptors: eg: (note this is for FreeBSD using daemon, but "nohup" should work on linux) daemon /usr/bin/env bash -c 'exec 0<&-; exec 1> /path/to/error/log; exec 2> /path/to/stdout/log; eval exec {3..255}\>\&-; /usr/bin/env php /path/to/script args...' Note we find it crucial to redirect and NOT CLOSE STDOUT and STDERR because otherwise you will never find out if sth is wrong with forked process. You should ensure that they exist and are writable before forking. The trick with eval exec {3..255}\>\&-; is from here: http://blog.n01se.net/blog-n01se-net-p-145.html This works for us in a php-fastcgi situation. the fastcgi-socket and the mysql socket are both closed successfully. the new process opens its own mysql socket just fine... I suspect this is similar to what Jeroen's closedexec.c does, but no need for a c program. Everyone should have bash. If you redirect the stdout of above fork command to a file and check the contents of that daemon gives you nice messages, just append 2> /path/to/temp/stderr/file/for/daemon/messages to the above command. We have the construction of the fork command wrapped in a simple function, like so: $exec_cmd = ((php_uname('s') == 'FreeBSD') ? 'daemon' : 'nohup') . // try to be OS agnostic, daemon = fork, setguid etc, but don't close stderr with -f ' /usr/bin/env bash -c ' . // wrap actual call to new php process in a shell (use env!), so // must escape here in case the already escaped args contain // specials chars like single quotes (which the will!) escapeshellarg( 'exec 0<&-; ' . // close STDIN 'exec 1> ' . escapeshellarg($app_log) . '; ' . // STDOUT > app_log 'exec 2> ' . escapeshellarg($error_log) . '; ' . // STDOUT > error_log 'eval exec {3..255}\>\&-; ' . // we can close all other fds (fastcgi, mysql, etc)..eval trick! '/usr/bin/env php ' . BASE . $cmd . ' ' . // call php (with env!) don't rely on shebang or exec perms join(' ', // add args separated by spaces array_map(function ($arg) { return escapeshellarg($arg); }, $args)) // after escaping them ); Sorry about the formatting... ------------------------------------------------------------------------ [2010-04-16 01:31:48] crrodriguez at opensuse dot org In linux, this should fix the issue for mail() diff --git a/ext/standard/mail.c b/ext/standard/mail.c index ab65f16..a8b3bf5 100644 --- a/ext/standard/mail.c +++ b/ext/standard/mail.c @@ -288,8 +288,12 @@ PHPAPI int php_mail(char *to, char *subject, char *message, char *headers, char * (e.g. the shell can't be executed) we explicitely set it to 0 to be * sure we don't catch any older errno value. */ errno = 0; +#if defined(__linux__) && defined(__GLIBC__) && __GLIBC_PREREQ(2, 9) + sendmail = popen(sendmail_cmd, "we"); +#else sendmail = popen(sendmail_cmd, "w"); #endif +#endif if (extra_cmd != NULL) { efree (sendmail_cmd); } Note that you need glibc 2.9 though. ------------------------------------------------------------------------ [2010-02-22 19:16:37] ionut dot dumitru at webland dot ro the problem is still there in 5.2 just with php not involving apache. so i write a cli daemon A which uses a listener socket , at some point it starts another daemon B with any of exec/system/popen etc. 'A' works as a sort of supervisor for B so i can't shut it down. but at some point i need to restart A, well I can't cause it won't bind to the same listener address anymore because B is keeping the handles open. spent a lot of time but i guess i have to go the file/cron way since php can't clean itself. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. 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