usb: host: u132-hcd: Fix a sleep-in-atomic-context bug in u132_get_frame()

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>

diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index c38855aed62c7df6ef3c7e134eae2c9b0e787da2..65c0086e25ae6d8ac1a302308e954ef15d88c41d 100644 (file)
--- a/drivers/usb/host/u132-hcd.c
+++ b/drivers/usb/host/u132-hcd.c
@@ -2559,7 +2559,7 @@ static int u132_get_frame(struct usb_hcd *hcd)
        } else {
                int frame = 0;
                dev_err(&u132->platform_dev->dev, "TODO: u132_get_frame\n");
-               msleep(100);
+               mdelay(100);
                return frame;
        }
 }