Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/directory v6

[Cyrill Gorcunov]

On Wed, Aug 31, 2011 at 01:06:12PM +0400, Vasiliy Kulikov wrote:
> Hi,
> 
> On Wed, Aug 31, 2011 at 11:58 +0400, Cyrill Gorcunov wrote:
> > From: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
> > 
> > This one behaves similarly to the /proc/<pid>/fd/ one - it contains symlinks
> > one for each mapping with file, the name of a symlink is "vma->vm_start-vma->vm_end",
> > the target is the file. Opening a symlink results in a file that point exactly
> > to the same inode as them vma's one.
> 
> I'm late noting it before the RFCv6 :)  Besides checking
> ptrace_may_access() on ->lookup and ->readdir you also should define
> ->stat, otherwise you can bypass ptrace checks if there is a
> corresponding dentry in the cache.  The same issue existed in fd* handlers:
> 
> http://www.openwall.com/lists/kernel-hardening/2011/08/29/1
> 

Yeah, good point, thanks Vasiliy.

	Cyrill
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/