diff options
| author | Murad Masimov <m.masimov@mt-integration.ru> | 2025-01-13 13:51:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-10 14:33:43 +0200 |
| commit | 30ef7cfee752ca318d5902cb67b60d9797ccd378 (patch) | |
| tree | e7128e3047989eacb75518429e51dc9f6465dbe7 | |
| parent | 78f06805cf86b4c2a150377d4ae4ef5405326301 (diff) | |
| download | linux-30ef7cfee752ca318d5902cb67b60d9797ccd378.tar.gz linux-30ef7cfee752ca318d5902cb67b60d9797ccd378.tar.bz2 linux-30ef7cfee752ca318d5902cb67b60d9797ccd378.zip | |
media: streamzap: fix race between device disconnection and urb callback
commit f656cfbc7a293a039d6a0c7100e1c846845148c1 upstream.
Syzkaller has reported a general protection fault at function
ir_raw_event_store_with_filter(). This crash is caused by a NULL pointer
dereference of dev->raw pointer, even though it is checked for NULL in
the same function, which means there is a race condition. It occurs due
to the incorrect order of actions in the streamzap_disconnect() function:
rc_unregister_device() is called before usb_kill_urb(). The dev->raw
pointer is freed and set to NULL in rc_unregister_device(), and only
after that usb_kill_urb() waits for in-progress requests to finish.
If rc_unregister_device() is called while streamzap_callback() handler is
not finished, this can lead to accessing freed resources. Thus
rc_unregister_device() should be called after usb_kill_urb().
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 8e9e60640067 ("V4L/DVB: staging/lirc: port lirc_streamzap to ir-core")
Cc: stable@vger.kernel.org
Reported-by: syzbot+34008406ee9a31b13c73@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=34008406ee9a31b13c73
Signed-off-by: Murad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/media/rc/streamzap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/media/rc/streamzap.c b/drivers/media/rc/streamzap.c index 9b209e687f25..2ce62fe5d60f 100644 --- a/drivers/media/rc/streamzap.c +++ b/drivers/media/rc/streamzap.c @@ -385,8 +385,8 @@ static void streamzap_disconnect(struct usb_interface *interface) if (!sz) return; - rc_unregister_device(sz->rdev); usb_kill_urb(sz->urb_in); + rc_unregister_device(sz->rdev); usb_free_urb(sz->urb_in); usb_free_coherent(usbdev, sz->buf_in_len, sz->buf_in, sz->dma_in); |