Merge "mw.widgets.CategorySelector: Avoid JS exceptions for invalid user input"

[lhc/web/wiklou.git] / includes / GlobalFunctions.php

diff --git a/includes/GlobalFunctions.php b/includes/GlobalFunctions.php
index 618fa4c..66e2440 100644 (file)
--- a/includes/GlobalFunctions.php
+++ b/includes/GlobalFunctions.php
@@ -30,7 +30,6 @@ use MediaWiki\Session\SessionManager;
 
 // Hide compatibility functions from Doxygen
 /// @cond
-
 /**
  * Compatibility functions
  *
@@ -2457,6 +2456,15 @@ function wfShellExec( $cmd, &$retval = null, $environ = [],
        }
        wfDebug( "wfShellExec: $cmd\n" );
 
+       // Don't try to execute commands that exceed Linux's MAX_ARG_STRLEN.
+       // Other platforms may be more accomodating, but we don't want to be
+       // accomodating, because very long commands probably include user
+       // input. See T129506.
+       if ( strlen( $cmd ) > SHELL_MAX_ARG_STRLEN ) {
+               throw new Exception( __METHOD__ .
+                       '(): total length of $cmd must not exceed SHELL_MAX_ARG_STRLEN' );
+       }
+
        $desc = [
                0 => [ 'file', 'php://stdin', 'r' ],
                1 => [ 'pipe', 'w' ],
@@ -2491,14 +2499,6 @@ function wfShellExec( $cmd, &$retval = null, $environ = [],
        $eintr = defined( 'SOCKET_EINTR' ) ? SOCKET_EINTR : 4;
        $eintrMessage = "stream_select(): unable to select [$eintr]";
 
-       // Build a table mapping resource IDs to pipe FDs to work around a
-       // PHP 5.3 issue in which stream_select() does not preserve array keys
-       // <https://bugs.php.net/bug.php?id=53427>.
-       $fds = [];
-       foreach ( $pipes as $fd => $pipe ) {
-               $fds[(int)$pipe] = $fd;
-       }
-
        $running = true;
        $timeout = null;
        $numReadyPipes = 0;
@@ -2531,9 +2531,8 @@ function wfShellExec( $cmd, &$retval = null, $environ = [],
                                break;
                        }
                }
-               foreach ( $readyPipes as $pipe ) {
+               foreach ( $readyPipes as $fd => $pipe ) {
                        $block = fread( $pipe, 65536 );
-                       $fd = $fds[(int)$pipe];
                        if ( $block === '' ) {
                                // End of file
                                fclose( $pipes[$fd] );