[PATCH-2.6.32.y-3.4.y] staging: comedi: pcmuio: fix possible NULL deref on detach

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



follow 2fd2bdfccae61efe18f6b92b6a45fbf936d75b48

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>
---
Applies to 2.6.32.y through to 3.4.y inclusive.
Does not apply to 3.5.y onwards.
---
 drivers/staging/comedi/drivers/pcmuio.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/comedi/drivers/pcmuio.c b/drivers/staging/comedi/drivers/pcmuio.c
index 661ba2e..6e936c5 100644
--- a/drivers/staging/comedi/drivers/pcmuio.c
+++ b/drivers/staging/comedi/drivers/pcmuio.c
@@ -464,13 +464,13 @@ static int pcmuio_detach(struct comedi_device *dev)
 	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;
 }
-- 
1.8.4.4

--
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




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]