Re: CVE request -- kernel: cifs: dentry refcount leak when opening a FIFO on lookup leads to panic on unmount

[Kurt Seifried <kseifried () redhat com>]

On 02/28/2012 08:15 AM, Petr Matousek wrote:
> The cifs code will attempt to open files on lookup under certain
> circumstances. What happens though if we find that the file we opened
> was actually a FIFO or other special file? Currently, the open
> filehandle just ends up being leaked leading to a dentry refcount
> mismatch and oops on umount.
>
> An unprivileged local user could use this flaw to crash the system.
>
> Introduced by:
> a6ce4932fbdbcd8f8e8c6df76812014351c32892 (Linux kernel 2.6.31)
>
> Proposed upstream patch:
> http://thread.gmane.org/gmane.linux.kernel.cifs/5526
>
> References:
> https://bugzilla.redhat.com/show_bug.cgi?id=798293
> http://thread.gmane.org/gmane.linux.kernel.cifs/5526
>
> Thanks,

Please use CVE-2012-1090 for this issue.

-- 
Kurt Seifried Red Hat Security Response Team (SRT)