USB: ldusb: fix NULL-derefs on driver unbind
authorJohan Hovold <johan@kernel.org>
Wed, 9 Oct 2019 15:38:46 +0000 (17:38 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 17 Oct 2019 20:42:37 +0000 (13:42 -0700)
commitf56ae521d30e0a4cb97dfb8da27a115814eed71d
tree69bc642a565f1363be3ce5477b37a479656279bf
parent697bd634c765667892d21e182792c94c92f813ea
USB: ldusb: fix NULL-derefs on driver unbind

commit 58ecf131e74620305175a7aa103f81350bb37570 upstream.

The driver was using its struct usb_interface pointer as an inverted
disconnected flag, but was setting it to NULL before making sure all
completion handlers had run. This could lead to a NULL-pointer
dereference in a number of dev_dbg, dev_warn and dev_err statements in
the completion handlers which relies on said pointer.

Fix this by unconditionally stopping all I/O and preventing
resubmissions by poisoning the interrupt URBs at disconnect and using a
dedicated disconnected flag.

This also makes sure that all I/O has completed by the time the
disconnect callback returns.

Fixes: 2824bd250f0b ("[PATCH] USB: add ldusb driver")
Cc: stable <stable@vger.kernel.org> # 2.6.13
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/misc/ldusb.c