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July 31, 2005
Httpd Exited on Signal 11 - Caused by Buggy Script
My security run output of today contains lots of error messages like:
pid 90742 (httpd), uid 80: exited on signal 11
pid 90896 (httpd), uid 80: exited on signal 11
It looks like a serious problem, then I searched the Internet immediately, here is a helpful discussion. Although there are no definite answers, the possible reasons can be summarized as:
1. Hardware problems, the most common one.
2. Vulnerable version of Apache, PHP or other Apache modules.
3. Buggy scripts.
Regarding my server
1. Hardware problems
This server has been running well for several months, unlikely to be the case.
2. Vulnerable version of Apache or its modules
Normally I can ignore this since I monitor the packages closely with portaudit. But recently Apache did have a known vulnerability. I ignored the upgrade because it shouldn't affect my installation.
This only affects installations where Apache is used as HTTP proxy in combination with the following web servers.
3. Buggy scripts
I did install mambo yesterday and it has a very weird problem, admin login doesn't work. There are many similar bug reports without solutions on their support forum, which is very unusual for a popular CMS, IMO. I debugged the script as I wrote in a previous post, it turned out that the login script ended at a PHP function "session_start()", it didn't give any error message, just like calling "die()". Then I made a test, signal 11 error happened every time I made a login.
Now the problem is clear, I removed mambo.
Category : Apache PHP
Posted by FreeBSD Newbie at July 31, 2005 02:05 PM
Comments
I maybe encountered a 4th case of sig11.
I'm using Apache 2.0 with PHP5 in a strictly configured environment using resource limits and I relatively often saw dying http processes through sig11.
Now I increased datasize and memoryuse in my login.conf for the desired Apache users and the problem seems to be solved.
Posted by Bernhard R. Fischer at November 10, 2005 01:38 PM