[PATCH 3.18 087/105] usb: host: u132-hcd: Fix a sleep-in-atomic-context bug in u132_get_frame()

From: Greg Kroah-Hartman
Date: Mon Sep 24 2018 - 07:42:02 EST

3.18-stable review patch. If anyone has any objections, please let me know.


From: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>

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@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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
@@ -2569,7 +2569,7 @@ 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;