Bug 47138

Summary: Reverse Proxy & Balancer generate error fault when shutting down on windows
Product: Apache httpd-2 Reporter: Duane Buss <dbuss>
Component: mod_proxyAssignee: Apache HTTPD Bugs Mailing List <bugs>
Status: RESOLVED LATER    
Severity: normal Keywords: MassUpdate
Priority: P2    
Version: 2.2.11   
Target Milestone: ---   
Hardware: PC   
OS: Windows Server 2003   
Attachments: patch for ~2.2.11

Description Duane Buss 2009-05-01 15:27:16 UTC
Created attachment 23591 [details]
patch for ~2.2.11

Improperly shared resources?

 While shutting down a debug version of apache on a windows server 2003 with debug MSDev libraries,  the underlying os libraries were complaining about the double free of a block of memory.   
 
  It appears that when ap_proxy_add_worker_to_balancer(apr_pool_t *pool, proxy_balancer *balancer, proxy_worker *worker) is called it uses memcpy to duplicate the proxy worker but doesn't do anything to change the cleanup routines or to make it's own copy of allocated resources like the pool and possibly the semaphore.  This results in two proxy workers structures each pointing to the same pool and semaphore.  
 
  During cleanup the original worker and the balancer worker each free their pool (which is the same pool), resulting in the pool being placed in the pool free list twice, now when the memory is freed there will be a double free of the memory representing the pool.
 
My patch for the issue is attached.
Comment 1 William A. Rowe Jr. 2018-11-07 21:09:35 UTC
Please help us to refine our list of open and current defects; this is a mass update of old and inactive Bugzilla reports which reflect user error, already resolved defects, and still-existing defects in httpd.

As repeatedly announced, the Apache HTTP Server Project has discontinued all development and patch review of the 2.2.x series of releases. The final release 2.2.34 was published in July 2017, and no further evaluation of bug reports or security risks will be considered or published for 2.2.x releases. All reports older than 2.4.x have been updated to status RESOLVED/LATER; no further action is expected unless the report still applies to a current version of httpd.

If your report represented a question or confusion about how to use an httpd feature, an unexpected server behavior, problems building or installing httpd, or working with an external component (a third party module, browser etc.) we ask you to start by bringing your question to the User Support and Discussion mailing list, see [https://httpd.apache.org/lists.html#http-users] for details. Include a link to this Bugzilla report for completeness with your question.

If your report was clearly a defect in httpd or a feature request, we ask that you retest using a modern httpd release (2.4.33 or later) released in the past year. If it can be reproduced, please reopen this bug and change the Version field above to the httpd version you have reconfirmed with.

Your help in identifying defects or enhancements still applicable to the current httpd server software release is greatly appreciated.