Bug #63377 [Csd]: Segfault on output buffer > 2GB
| From: | laruence@php.net | Date: | Fri, 30 Nov 2012 06:51:36 +0000 |
| Subject: | Bug #63377 [Csd]: Segfault on output buffer > 2GB | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-175040@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=63377&edit=1
ID: 63377
Updated by: laruence@php.net
Reported by: miau dot jp at gmail dot com
Summary: Segfault on output buffer > 2GB
Status: Closed
Type: Bug
Package: Output Control
Operating System: Linux
PHP Version: 5.3.18
-Assigned To: mike
+Assigned To: laruence
Block user comment: N
Private report: N
New Comment:
The fix for this bug has been committed.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
For Windows:
http://windows.php.net/snapshots/
Thank you for the report, and for helping us make PHP better.
Previous Comments:
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[2012-11-30 06:50:15] laruence@php.net
Automatic comment on behalf of laruence
Revision: http://git.php.net/?p=php-src.git;a=commit;h=ff6c9e2726ab724707999ed651d1a414336665f2
Log: Fixed bug #63377 (Segfault on output buffer)
------------------------------------------------------------------------
[2012-11-30 06:49:42] laruence@php.net
Automatic comment on behalf of laruence
Revision: http://git.php.net/?p=php-src.git;a=commit;h=ff6c9e2726ab724707999ed651d1a414336665f2
Log: Fixed bug #63377 (Segfault on output buffer)
------------------------------------------------------------------------
[2012-11-30 06:49:16] laruence@php.net
Automatic comment on behalf of laruence
Revision: http://git.php.net/?p=php-src.git;a=commit;h=ff6c9e2726ab724707999ed651d1a414336665f2
Log: Fixed bug #63377 (Segfault on output buffer)
------------------------------------------------------------------------
[2012-11-30 06:48:42] laruence@php.net
Automatic comment on behalf of laruence
Revision: http://git.php.net/?p=php-src.git;a=commit;h=ff6c9e2726ab724707999ed651d1a414336665f2
Log: Fixed bug #63377 (Segfault on output buffer)
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[2012-10-28 19:59:33] miau dot jp at gmail dot com
Description:
------------
Storing data more than 2GB cause a segmentation fault. This problem seems
occur on implicit use of output buffer, such as print_r($val, true).
I ran the test script with GDB.
----
(gdb) run ob.php
Starting program: /usr/local/php-5.3.18/bin/php ob.php
warning: no loadable sections found in added symbol-file system-supplied DSO at
0x2aaaaaaab000
[Thread debugging using libthread_db enabled]
Program received signal SIGSEGV, Segmentation fault.
0x0000000000597cb3 in php_ob_append (text=0x2aaaae1ae070 'a' <repeats 200
times>..., text_length=104857600)
at /usr/local/src/php-5.3.18/main/output.c:616
616 memcpy(target, text, text_length);
(gdb) l 607,616
607 static inline void php_ob_append(const char *text, uint text_length
TSRMLS_DC)
608 {
609 char *target;
610 int original_ob_text_length;
611
612 original_ob_text_length=OG(active_ob_buffer).text_length;
613
614 php_ob_allocate(text_length TSRMLS_CC);
615 target = OG(active_ob_buffer).buffer+original_ob_text_length;
616 memcpy(target, text, text_length);
(gdb) p target
$1 = 0x2aaa379ef070 <Address 0x2aaa379ef070 out of bounds>
(gdb) p output_globals.active_ob_buffer.buffer
$2 = 0x2aaab45ef070 'a' <repeats 200 times>...
(gdb) p original_ob_text_length
$3 = -2092957696
original_ob_text_length is wrongly recognized as a negative value and
address of target is less than output_globals.active_ob_buffer.buffer.
Declaring original_ob_text_length as uint will fix this problem.
Test script:
---------------
<?php
ini_set('memory_limit', '3072M');
ob_start();
for ($i = 0; $i < 22; $i++) {
echo str_repeat('a', 100 * 1024 * 1024);
}
ob_end_clean();
Expected result:
----------------
# php ob.php
(no error occurs)
Actual result:
--------------
(Since a fatal error sometimes cause ob_flush(), redirecting
STDOUT is preferable.)
# php ob.php > /dev/null
Segmentation fault
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--
Edit this bug report at https://bugs.php.net/bug.php?id=63377&edit=1