This is a note to let you know that I've just added the patch titled wimax/i2400m: Fix potential urb refcnt leak to the 4.4-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: wimax-i2400m-fix-potential-urb-refcnt-leak.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5e027e4bbfc73b3cce34c4437fa470c6197a8f77 Author: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Date: Wed Apr 15 16:41:20 2020 +0800 wimax/i2400m: Fix potential urb refcnt leak [ Upstream commit 7717cbec172c3554d470023b4020d5781961187e ] i2400mu_bus_bm_wait_for_ack() invokes usb_get_urb(), which increases the refcount of the "notif_urb". When i2400mu_bus_bm_wait_for_ack() returns, local variable "notif_urb" becomes invalid, so the refcount should be decreased to keep refcount balanced. The issue happens in all paths of i2400mu_bus_bm_wait_for_ack(), which forget to decrease the refcnt increased by usb_get_urb(), causing a refcnt leak. Fix this issue by calling usb_put_urb() before the i2400mu_bus_bm_wait_for_ack() returns. Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/wimax/i2400m/usb-fw.c b/drivers/net/wimax/i2400m/usb-fw.c index e74664b84925e..4e4167976acf6 100644 --- a/drivers/net/wimax/i2400m/usb-fw.c +++ b/drivers/net/wimax/i2400m/usb-fw.c @@ -354,6 +354,7 @@ ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *i2400m, usb_autopm_put_interface(i2400mu->usb_iface); d_fnend(8, dev, "(i2400m %p ack %p size %zu) = %ld\n", i2400m, ack, ack_size, (long) result); + usb_put_urb(¬if_urb); return result; error_exceeded: