4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jia-Ju Bai baijiaju1990@gmail.com
commit 6d4f268fa132742fe96dad22307c68d237356d88 upstream.
i_usX2Y_subs_startup in usbusx2yaudio.c is a completion handler function for the USB driver. So it should not sleep, but it is can sleep according to the function call paths (from bottom to top) in Linux-4.16.
[FUNC] msleep drivers/usb/host/u132-hcd.c, 2558: msleep in u132_get_frame drivers/usb/core/hcd.c, 2231: [FUNC_PTR]u132_get_frame in usb_hcd_get_frame_number drivers/usb/core/usb.c, 822: usb_hcd_get_frame_number in usb_get_current_frame_number sound/usb/usx2y/usbusx2yaudio.c, 303: usb_get_current_frame_number in i_usX2Y_urb_complete sound/usb/usx2y/usbusx2yaudio.c, 366: i_usX2Y_urb_complete in i_usX2Y_subs_startup
Note that [FUNC_PTR] means a function pointer call is used.
To fix this bug, msleep() is replaced with mdelay().
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai baijiaju1990@gmail.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/host/u132-hcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/host/u132-hcd.c +++ b/drivers/usb/host/u132-hcd.c @@ -2565,7 +2565,7 @@ static int u132_get_frame(struct usb_hcd } else { int frame = 0; dev_err(&u132->platform_dev->dev, "TODO: u132_get_frame\n"); - msleep(100); + mdelay(100); return frame; } }