This is a note to let you know that I've just added the patch titled staging: comedi: pcmuio: fix possible NULL deref on detach to the 3.4-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-pcmuio-fix-possible-null-deref-on-detach.patch and it can be found in the queue-3.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 2fd2bdfccae61efe18f6b92b6a45fbf936d75b48 Mon Sep 17 00:00:00 2001 From: Ian Abbott <abbotti@xxxxxxxxx> Date: Tue, 20 Aug 2013 11:50:19 +0100 Subject: staging: comedi: pcmuio: fix possible NULL deref on detach From: Ian Abbott <abbotti@xxxxxxxxx> commit 2fd2bdfccae61efe18f6b92b6a45fbf936d75b48 upstream. pcmuio_detach() is called by the comedi core even if pcmuio_attach() returned an error, so `dev->private` might be `NULL`. Check for that before dereferencing it. Also, as pointed out by Dan Carpenter, there is no need to check the pointer passed to `kfree()` is non-NULL, so remove that check. Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/comedi/drivers/pcmuio.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/drivers/staging/comedi/drivers/pcmuio.c +++ b/drivers/staging/comedi/drivers/pcmuio.c @@ -464,13 +464,13 @@ static int pcmuio_detach(struct comedi_d if (dev->iobase) release_region(dev->iobase, ASIC_IOSIZE * thisboard->num_asics); - for (i = 0; i < MAX_ASICS; ++i) { - if (devpriv->asics[i].irq) - free_irq(devpriv->asics[i].irq, dev); - } - - if (devpriv && devpriv->sprivs) + if (devpriv) { + for (i = 0; i < MAX_ASICS; ++i) { + if (devpriv->asics[i].irq) + free_irq(devpriv->asics[i].irq, dev); + } kfree(devpriv->sprivs); + } return 0; } Patches currently in stable-queue which might be from abbotti@xxxxxxxxx are queue-3.4/staging-comedi-pcmuio-fix-possible-null-deref-on-detach.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html