A bug has been found in Samba that can allow an authenticated user to cause a child smbd process to enter an infinite loop. The definition is rather complicated so I'm going to paste the description from the upstream Samba advisory: Internally Samba's file server daemon, smbd, implements support for deferred file open calls in an attempt to serve client requests that would otherwise fail due to a share mode violation. When renaming a file under certain circumstances it is possible that the request is never removed from the deferred open queue. smbd will then become stuck is a loop trying to service the open request. This bug may allow an authenticated user to exhaust resources such as memory and CPU on the server by opening multiple CIFS sessions, each of which will normally spawn a new smbd process, and sending each connection into an infinite loop.
This flaw also affects RHEL3
Created attachment 146985 [details] Proposed upstream patch
This is RHSA-2007:0060
This flaw is now public: http://us1.samba.org/samba/security/CVE-2007-0452.html
*** Bug 227993 has been marked as a duplicate of this bug. ***
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2007-0060.html