linux/drivers/media/radio/si470x
Shigeru Yoshida 7d21e0b1b4 media: si470x: Fix use-after-free in si470x_int_in_callback()
syzbot reported use-after-free in si470x_int_in_callback() [1].  This
indicates that urb->context, which contains struct si470x_device
object, is freed when si470x_int_in_callback() is called.

The cause of this issue is that si470x_int_in_callback() is called for
freed urb.

si470x_usb_driver_probe() calls si470x_start_usb(), which then calls
usb_submit_urb() and si470x_start().  If si470x_start_usb() fails,
si470x_usb_driver_probe() doesn't kill urb, but it just frees struct
si470x_device object, as depicted below:

si470x_usb_driver_probe()
  ...
  si470x_start_usb()
    ...
    usb_submit_urb()
    retval = si470x_start()
    return retval
  if (retval < 0)
    free struct si470x_device object, but don't kill urb

This patch fixes this issue by killing urb when si470x_start_usb()
fails and urb is submitted.  If si470x_start_usb() fails and urb is
not submitted, i.e. submitting usb fails, it just frees struct
si470x_device object.

Reported-by: syzbot+9ca7a12fd736d93e0232@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=94ed6dddd5a55e90fd4bab942aa4bb297741d977 [1]
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
2022-12-07 17:58:47 +01:00
..
Kconfig media: Kconfig: cleanup VIDEO_DEV dependencies 2022-03-18 05:58:35 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
radio-si470x-common.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
radio-si470x-i2c.c i2c: Make remove callback return void 2022-08-16 12:46:26 +02:00
radio-si470x-usb.c media: si470x: Fix use-after-free in si470x_int_in_callback() 2022-12-07 17:58:47 +01:00
radio-si470x.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00