Bug #79549 [Opn->Ver]: PHP-FPM sends invalid headers '0\xd5e\xc8' to the web server

Edit report at https://bugs.php.net/bug.php?id=79549&edit=1 ID: 79549 Updated by: requinix@php.net Reported by: morozov at tut dot by Summary: PHP-FPM sends invalid headers '0\xd5e\xc8' to the web server -Status: Open +Status: Verified Type: Bug Package: opcache Operating System: Linux PHP Version: 7.4.5 Block user comment: N Private report: N New Comment: The important bit being 20:47:31.786 >>> process php-fpm [125706 -> 73344] len 152(152)

~Status: 304 Not Modified X-Powered-By: PHP/7.4.5 Cache-Control: max-age=0, private j Pragma: Content-Length: 2

ort I've confirmed that whole thing is indeed 152 bytes. You can take down the gist if you want, but just in case, please dump one of these outputs to a file and hang onto it in case it's useful. So yeah, definitely screwy: there's leading garbage before the headers, clearly something weird happened to the Expires, and there's more garbage before the body. Would you be able to try running on other PHP versions? I suggest 7.4.1 and a recent 7.3. Separately, notice that this is a 304 but it comes with some output. If your application is responsible for emitting that (and given the Content-Length header I think it is), it's incorrect behavior that you should look into when you have the time. Previous Comments: ------------------------------------------------------------------------ [2020-05-01 03:54:33] morozov at tut dot by Please see the dump at https://gist.github.com/morozov/bfe35ea3298681cf75b6ba54d67d2575 Right before the empty Pragma: header there was supposed to be the Expires: one. ------------------------------------------------------------------------ [2020-05-01 01:44:53] requinix@php.net I don't know, haven't done it before myself. Some quick leads for you to follow: https://github.com/mechpen/sockdump https://superuser.com/questions/484671/can-i-monitor-a-local-unix-domain-socket-like-tcpdump https://superuser.com/questions/23180/whats-the-easiest-way-to-sniff-tcp-traffic-data-on-linux ------------------------------------------------------------------------ [2020-05-01 01:35:32] morozov at tut dot by What's the recommended way of intercepting traffic between a web server and PHP FPM? I use a local Unix socket for development. Should I switch to TCP/IP and use something like Wireshark? ------------------------------------------------------------------------ [2020-05-01 00:59:40] requinix@php.net Is there any way you can dump the full response from php-fpm to somewhere you can read it? ------------------------------------------------------------------------ [2020-04-30 23:18:12] morozov at tut dot by Description: ------------ Under certain circumstances which I cannot currently isolate, PHP-FPM responds to the webserver (Apache) with certain invalid headers that result in a 500 response from apache. The issue is only reproducible in a proprietary application. There are certain criteria I was able to identify which make the issue trigger. If I remove any of them, the issue goes away: 1. Opcache enabled. 2. header('Expires:'); header('Pragma:'); // note the absence of the value which is probably invalid. Sometimes the issue is also reproducible even w/o invalid headers 3. Response length. With all other parameters the same, a "[]" json response doesn't cause the issue but a valid 180-bytes response does. 4. Some seemingly unrelated function calls like file_get_contents(). Actual result: -------------- Apache response: <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>500 Internal Server Error</title> </head><body> <h1>Internal Server Error</h1> <p>The server encountered an internal error or misconfiguration and was unable to complete your request.</p> <p>Please contact the server administrator at [no address given] to inform them of the time this error occurred, and the actions you performed just before this error.</p> <p>More information about this error may be available in the server error log.</p> <p>Additionally, a 304 Not Modified error was encountered while trying to use an ErrorDocument to handle the request.</p> <hr> <address>Apache/2.4.41 (Ubuntu) Server at sugarcrm.local Port 80</address> </body></html> Apache logs: [Thu Apr 30 14:57:39.470700 2020] [http:error] [pid 73344:tid 140477684762368] [client 127.0.0.1:35104] AH02429: Response header name '0\xd5e\xc8' contains invalid characters, aborting request, referer: ... [Thu Apr 30 14:57:39.725176 2020] [http:error] [pid 73311:tid 140478498461440] [client 127.0.0.1:35016] AH02429: Response header name '\x90\x84f\xc8' contains invalid characters, aborting request, referer: ... [Thu Apr 30 15:06:12.065188 2020] [http:error] [pid 73344:tid 140478162917120] [client 127.0.0.1:39432] AH02429: Response header name '0\x85f\xc8' contains invalid characters, aborting request, referer: ... [Thu Apr 30 15:14:17.448112 2020] [http:error] [pid 73344:tid 140478869321472] [client 127.0.0.1:43298] AH02429: Response header name 'p\x84f\xc8' contains invalid characters, aborting request, referer: ... [Thu Apr 30 15:43:12.482083 2020] [http:error] [pid 73344:tid 140478877714176] [client 127.0.0.1:57656] AH02429: Response header name '@\x84f\xc8' contains invalid characters, aborting request, referer: ... [Thu Apr 30 15:50:02.294075 2020] [http:error] [pid 73311:tid 140478246811392] [client 127.0.0.1:60500] AH02429: Response header name 'P\x84f\xc8' contains invalid characters, aborting request, referer: ... [Thu Apr 30 15:50:05.837520 2020] [http:error] [pid 73311:tid 140478230025984] [client 127.0.0.1:33090] AH02429: Response header name ' \x84f\xc8' contains invalid characters, aborting request, referer: ... ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79549&edit=1