This is a note to let you know that I've just added the patch titled

    staging: comedi: amplc_dio200: fix possible NULL deref during detach

to the 3.6-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     staging-comedi-amplc_dio200-fix-possible-null-deref-during-detach.patch
and it can be found in the queue-3.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From dfb2540e91e1f63765bc3ff497ad0b714d774261 Mon Sep 17 00:00:00 2001
From: Ian Abbott <[email protected]>
Date: Wed, 3 Oct 2012 16:25:16 +0100
Subject: staging: comedi: amplc_dio200: fix possible NULL deref during detach

From: Ian Abbott <[email protected]>

commit dfb2540e91e1f63765bc3ff497ad0b714d774261 upstream.

`dio200_detach()` is called by the comedi core to clean up if either
`dio200_attach()` or `dio200_attach_pci()` return an error.  It assigns
`thisboard` to the return value of `comedi_board(dev)` and assumes it is
non-null.  In the case of a previous call to `dio200_attach()` it won't
be `NULL` because the comedi core will have pointed it to one of the
elements of `dio200_boards[]`, but in the case of a previous call to
`dio200_attach_pci()` it could be `NULL`, leading to a null pointer
dereference.

Check that `thisboard` is valid at the top of `dio200_detach()` and
return early if it is `NULL`.  This is okay because the only other thing
that could have been allocated is `dev->private` and that is freed by
the comedi core, not by this function.

Signed-off-by: Ian Abbott <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/staging/comedi/drivers/amplc_dio200.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/staging/comedi/drivers/amplc_dio200.c
+++ b/drivers/staging/comedi/drivers/amplc_dio200.c
@@ -1429,6 +1429,8 @@ static void dio200_detach(struct comedi_
        const struct dio200_layout_struct *layout;
        unsigned n;
 
+       if (!thisboard)
+               return;
        if (dev->irq)
                free_irq(dev->irq, dev);
        if (dev->subdevices) {


Patches currently in stable-queue which might be from [email protected] are

queue-3.6/staging-comedi-amplc_pc263-fix-possible-null-deref-during-detach.patch
queue-3.6/staging-comedi-das08-fix-possible-null-deref-during-detach.patch
queue-3.6/staging-comedi-ni_daq_700-fix-dio-subdevice-regression.patch
queue-3.6/staging-comedi-amplc_pc236-fix-possible-null-deref-during-detach.patch
queue-3.6/staging-comedi-ni_labpc-fix-possible-null-deref-during-detach.patch
queue-3.6/staging-comedi-amplc_dio200-fix-possible-null-deref-during-detach.patch
queue-3.6/staging-comedi-amplc_pc236-fix-invalid-register-access-during-detach.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to