From bd1e7bc1dd3a4a70a0885cc674746834b13d23d4 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 22 Mar 2011 11:12:11 +0100 Subject: [PATCH] USB: cdc-acm: fix potential null-pointer dereference on disconnect commit 7e7797e7f6f7bfab73fca02c65e40eaa5bb9000c upstream. Fix potential null-pointer exception on disconnect introduced by commit 11ea859d64b69a747d6b060b9ed1520eab1161fe (USB: additional power savings for cdc-acm devices that support remote wakeup). Only access acm->dev after making sure it is non-null in control urb completion handler. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 7512dfdb7e0f..4e32da6a6d5d 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -297,6 +297,8 @@ static void acm_ctrl_irq(struct urb *urb) if (!ACM_READY(acm)) goto exit; + usb_mark_last_busy(acm->dev); + data = (unsigned char *)(dr + 1); switch (dr->bNotificationType) { case USB_CDC_NOTIFY_NETWORK_CONNECTION: @@ -336,7 +338,6 @@ static void acm_ctrl_irq(struct urb *urb) break; } exit: - usb_mark_last_busy(acm->dev); retval = usb_submit_urb(urb, GFP_ATOMIC); if (retval) dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with " -- 2.39.2