Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

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

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>

authored by

Jia-Ju Bai and committed by
Greg Kroah-Hartman
6d4f268f f9a5b4f5

+1 -1
+1 -1
drivers/usb/host/u132-hcd.c
··· 2555 2555 } else { 2556 2556 int frame = 0; 2557 2557 dev_err(&u132->platform_dev->dev, "TODO: u132_get_frame\n"); 2558 - msleep(100); 2558 + mdelay(100); 2559 2559 return frame; 2560 2560 } 2561 2561 }