Re: [PATCH] mm: Check we have the right vma in access_process_vm()

From: Michael Ellerman
Date: Fri Apr 08 2011 - 03:17:09 EST

On Mon, 2011-04-04 at 23:42 -0700, Michel Lespinasse wrote:
> On Mon, Apr 4, 2011 at 11:24 PM, Michael Ellerman
> <michael@xxxxxxxxxxxxxx> wrote:
> > In access_process_vm() we need to check that we have found the right
> > vma, not the following vma, before we try to access it. Otherwise
> > we might call the vma's access routine with an address which does
> > not fall inside the vma.
> >
> > Signed-off-by: Michael Ellerman <michael@xxxxxxxxxxxxxx>
> Please note that the code has moved into __access_remote_vm() in
> current linus tree.

Ah good point, if git hadn't done such a good job of merging it I would
have noticed :)

I'll send a new version with a corrected changelog.

> Also, should len be truncated before calling vma->vm_ops->access() so
> that we can guarantee it won't overflow past the end of the vma ?

The access implementations I've looked at check len, but I guess it
could be truncated on the way in. But maybe that's being paranoid, I


Attachment: signature.asc
Description: This is a digitally signed message part