CVE-2022-50542

In the Linux kernel, the following vulnerability has been resolved:

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() doesnt 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 dont 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.

Affected Software

References

• https://git.kernel.org/stable/c/0ca298d548461d29615f9a2b1309e8dcf4a352c6
• https://git.kernel.org/stable/c/146bd005ebb01ae190c22af050cb98623958c373
• https://git.kernel.org/stable/c/1c6447d0fc68650e51586dde79b5090d9d77f13a
• https://git.kernel.org/stable/c/52f54fe78cca24850a30865037250f63eb3d5bf7
• https://git.kernel.org/stable/c/63648a7bd1a7599bcc2040a6d1792363ae4c2e1b
• https://git.kernel.org/stable/c/6c8aee0c8fcc6dda94315f7908e8fa9bc75abe75
• https://git.kernel.org/stable/c/7d21e0b1b41b21d628bf2afce777727bd4479aa5
• https://git.kernel.org/stable/c/8c6151b8e8dd2d98ad2cd725d26d1e103d989891
• https://git.kernel.org/stable/c/92b0888398e4ba51d93b618a6506781f4e3879c9