diff options
| author | Johan Hovold <johan@kernel.org> | 2019-09-25 11:29:12 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-12-10 18:01:35 +0000 |
| commit | 22cbb8fb12b3b5101260915162ad2b0b56a9284d (patch) | |
| tree | 86a2636fe158289333d681f361e415a651c3ab14 | |
| parent | 669ddcc72d26dc8a6e8df7b4d1f0fa896b9748d2 (diff) | |
| download | linux-22cbb8fb12b3b5101260915162ad2b0b56a9284d.tar.gz linux-22cbb8fb12b3b5101260915162ad2b0b56a9284d.tar.bz2 linux-22cbb8fb12b3b5101260915162ad2b0b56a9284d.zip | |
USB: adutux: fix use-after-free on disconnect
commit 44efc269db7929f6275a1fa927ef082e533ecde0 upstream.
The driver was clearing its struct usb_device pointer, which it used as
an inverted disconnected flag, before deregistering the character device
and without serialising against racing release().
This could lead to a use-after-free if a racing release() callback
observes the cleared pointer and frees the driver data before
disconnect() is finished with it.
This could also lead to NULL-pointer dereferences in a racing open().
Fixes: f08812d5eb8f ("USB: FIx locks and urb->status in adutux (updated)")
Reported-by: syzbot+0243cb250a51eeefb8cc@syzkaller.appspotmail.com
Tested-by: syzbot+0243cb250a51eeefb8cc@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20190925092913.8608-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/usb/misc/adutux.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c index f6f7372dd2fb..065db5f4b62b 100644 --- a/drivers/usb/misc/adutux.c +++ b/drivers/usb/misc/adutux.c @@ -799,14 +799,15 @@ static void adu_disconnect(struct usb_interface *interface) dev = usb_get_intfdata(interface); - mutex_lock(&dev->mtx); /* not interruptible */ - dev->udev = NULL; /* poison */ usb_deregister_dev(interface, &adu_class); - mutex_unlock(&dev->mtx); mutex_lock(&adutux_mutex); usb_set_intfdata(interface, NULL); + mutex_lock(&dev->mtx); /* not interruptible */ + dev->udev = NULL; /* poison */ + mutex_unlock(&dev->mtx); + /* if the device is not opened, then we clean up right now */ if (!dev->open_count) adu_delete(dev); |