| From | Paul Gortmaker <> | Subject | [34-longterm 211/247] USB: cdc-acm: fix potential null-pointer dereference on disconnect | Date | Thu, 23 Jun 2011 13:34:39 -0400 |
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From: Johan Hovold <jhovold@gmail.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
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 <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/usb/class/cdc-acm.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index a45e6c4..073a9ef 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 " -- 1.7.4.4
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