From: tstarling at wikimedia dot org
Operating system: Linux
PHP version: 5.2CVS-2009-03-02 (CVS)
PHP Bug Type: *General Issues
Bug description: CLI can go into an infinite write() loop when
ignore_user_abort(true)
Description:
------------
sapi_cli_ub_write() is faulty and may go into a tight infinite loop under
certain circumstances. If write() produces an error, it calls
php_handle_aborted_connection(), but if ignore_user_abort(true) has been
called, this does not exit the request. Thus it enters an infinite loop.
Bug #20053 is a similar bug in a different SAPI. It's likely that many
SAPIs have copied this code and suffer the same problem.
Reproduce code:
---------------
<?php
ignore_user_abort(true);
while ( true ) {
fwrite( STDERR, microtime(true) . "\n" );
echo "Hello\n";
usleep(500000);
}
?>
Run it like this:
$ php nfs-test.php > /mnt/some-nfs-mount/test-file
Then while that is running, on another server:
$ rm /mnt/some-nfs-mount/test-file
Expected result:
----------------
It should exit when the file is removed, like it does when
ignore_user_abort(true) is not called.
Actual result:
--------------
After a few seconds, the stderr output will stop ticking, and strace will
show a flood of:
write(1, "Hello\n", 6) = -1 ESTALE (Stale NFS file
handle)
write(1, "Hello\n", 6) = -1 ESTALE (Stale NFS file
handle)
write(1, "Hello\n", 6) = -1 ESTALE (Stale NFS file
handle)
write(1, "Hello\n", 6) = -1 ESTALE (Stale NFS file
handle)
write(1, "Hello\n", 6) = -1 ESTALE (Stale NFS file
handle)
write(1, "Hello\n", 6) = -1 ESTALE (Stale NFS file
handle)
--
Edit bug report at http://bugs.php.net/?id=47540&edit=1
--
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=47540&r=trysnapshot52
Try a CVS snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=47540&r=trysnapshot53
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=47540&r=trysnapshot60
Fixed in CVS:
http://bugs.php.net/fix.php?id=47540&r=fixedcvs
Fixed in CVS and need be documented:
http://bugs.php.net/fix.php?id=47540&r=needdocs
Fixed in release:
http://bugs.php.net/fix.php?id=47540&r=alreadyfixed
Need backtrace:
http://bugs.php.net/fix.php?id=47540&r=needtrace
Need Reproduce Script:
http://bugs.php.net/fix.php?id=47540&r=needscript
Try newer version:
http://bugs.php.net/fix.php?id=47540&r=oldversion
Not developer issue:
http://bugs.php.net/fix.php?id=47540&r=support
Expected behavior:
http://bugs.php.net/fix.php?id=47540&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=47540&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=47540&r=submittedtwice
register_globals:
http://bugs.php.net/fix.php?id=47540&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=47540&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=47540&r=dst
IIS Stability:
http://bugs.php.net/fix.php?id=47540&r=isapi
Install GNU Sed:
http://bugs.php.net/fix.php?id=47540&r=gnused
Floating point limitations:
http://bugs.php.net/fix.php?id=47540&r=float
No Zend Extensions:
http://bugs.php.net/fix.php?id=47540&r=nozend
MySQL Configuration Error:
http://bugs.php.net/fix.php?id=47540&r=mysqlcfg
