Created attachment 366258 [details] Short example reproducing the crash The attached script crash Python. The callback is shared between the two processes, the child destroy the callback, and then the parent uses the callback (re-destroy the callback). The crash is specific to SELinux, it doesn't crash on another OS without SELinux. I have the bug on Fedora 12 Beta and Python 2.6.2. I posted the bug to the libffi mailing list: http://sourceware.org/ml/libffi-discuss/2009/msg00320.html The bug should be fixed in libffi, but I opened a bug for your information, and to track the bug in Fedora.
Thanks for filing this bug. Our python RPMs use the system libffi; reassigning component from "python" to "libffi".
This bug appears to have been reported against 'rawhide' during the Fedora 12 development cycle. Changing version to '12'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Here's the mailing list discussion. http://old.nabble.com/bug-in-libffi-with-selinux-and-a-fork-td26076869.html I'm not sure I understand the proposed solution. Could somebody dumb it down for me? Jakub wrote: > perhaps > closures.c should record the pid of the current process and if it notices a > different pid, it should reinitialize all its global variables to make sure > the file isn't shared nor the mappings. Are we talking about the following from closures.c? open_temp_exec_file_mutex execfd execsize open_temp_exec_file_opts_idx Andrew - you suggested checking for the PID change when destroying the closure. How would you do that? Thanks!
It would be nice simply to say that processes can only destroy callbacks they created themselves. But this won't really work, since there is a common memory pool that's being used by both processes. What we *really* need is to make the pages that contain the callbacks copy-on-write in the child process. Without some sort of atfork() I'm not sure anything can be done about this.
This message is a reminder that Fedora 12 is nearing its end of life. Approximately 30 (thirty) days from now Fedora will stop maintaining and issuing updates for Fedora 12. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as WONTFIX if it remains open with a Fedora 'version' of '12'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version prior to Fedora 12's end of life. Bug Reporter: Thank you for reporting this issue and we are sorry that we may not be able to fix it before Fedora 12 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora please change the 'version' of this bug to the applicable version. If you are unable to change the version, please add a comment here and someone will do it for you. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. The process we are following is described here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Fedora 12 changed to end-of-life (EOL) status on 2010-12-02. Fedora 12 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. Thank you for reporting this bug and we are sorry it could not be fixed.