This is a note to let you know that I've just added the patch titled
media: si470x: Fix use-after-free in si470x_int_in_callback()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-si470x-fix-use-after-free-in-si470x_int_in_cal.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d7ed80959ad56f506bce1a3ba6abb482c4156912
Author: Shigeru Yoshida <syoshida@xxxxxxxxxx>
Date: Wed Nov 23 03:51:59 2022 +0900
media: si470x: Fix use-after-free in si470x_int_in_callback()
[ Upstream commit 7d21e0b1b41b21d628bf2afce777727bd4479aa5 ]
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@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?id=94ed6dddd5a55e90fd4bab942aa4bb297741d977 [1]
Signed-off-by: Shigeru Yoshida <syoshida@xxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/radio/si470x/radio-si470x-usb.c b/drivers/media/radio/si470x/radio-si470x-usb.c
index 3f8634a46573..1365ae732b79 100644
--- a/drivers/media/radio/si470x/radio-si470x-usb.c
+++ b/drivers/media/radio/si470x/radio-si470x-usb.c
@@ -733,8 +733,10 @@ static int si470x_usb_driver_probe(struct usb_interface *intf,
/* start radio */
retval = si470x_start_usb(radio);
- if (retval < 0)
+ if (retval < 0 && !radio->int_in_running)
goto err_buf;
+ else if (retval < 0) /* in case of radio->int_in_running == 1 */
+ goto err_all;
/* set initial frequency */
si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
