Bug #81589 [NEW]: PHP script on FPM / FastCGI may end prematurely

From: peter dot kotuliak at gmail dot com Operating system: Linux PHP version: Irrelevant Package: FPM related Bug Type: Bug Bug description:PHP script on FPM / FastCGI may end prematurely Description: ------------ Running provided test script (error reporting cannot be Off) on real webserver (Apache, nginx tested) using php-fpm, ends prematurely. This is FPM specific bug (e.g. use of Apache handler is OK). Script "terminates" because FPM sometimes generates empty (zero length) FCGI record / packet. FCGI specification however states that such a record may indicate content termination. Solution is to replace this code in fastcgi.c } else if (len - limit < (int)(sizeof(req->out_buf) - sizeof(fcgi_header))) { if (!req->out_hdr) { open_packet(req, type); } if (limit > 0) { memcpy(req->out_pos, str, limit); req->out_pos += limit; } if (!fcgi_flush(req, 0)) { with this } else if (len - limit < (int)(sizeof(req->out_buf) - sizeof(fcgi_header))) { if (limit > 0) { if (!req->out_hdr) { open_packet(req, type); } memcpy(req->out_pos, str, limit); req->out_pos += limit; } if (!fcgi_flush(req, 0)) { It solves bug, occurring when stream changes (from OUT to ERR or vice versa), but having too few bytes left in output buffer (in this case, first it is called close_packet due to stream change and since limit==0 additional open_packet and close_packet (inside fcgi_flush) is called with zero content length, which webserver interprets as "request finished"). Script has to be tested on real webserver (FPM tester used in .phpt does not copy webserver behavior that well in this case). Every PHP version is affected. If you have any questions, or trouble reproducing bug, please contact me. Test script: --------------- <?php for($i=0;$i<167;$i++){ error_log('PHP is the best programming language'); } echo 'end'; ?> Expected result: ---------------- string "end" Actual result: -------------- empty string -- Edit bug report at https://bugs.php.net/bug.php?id=81589&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=81589&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=81589&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=81589&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=81589&r=needscript Try newer version: https://bugs.php.net/fix.php?id=81589&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=81589&r=support Expected behavior: https://bugs.php.net/fix.php?id=81589&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=81589&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=81589&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=81589&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=81589&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=81589&r=dst IIS Stability: https://bugs.php.net/fix.php?id=81589&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=81589&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=81589&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=81589&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=81589&r=mysqlcfg