comedi: ni_usb6501: fix NULL-deref in command paths

stable inclusion
from stable-v5.10.79
commit ef143dc0c3defe56730ecd3a9de7b3e1d7e557c1
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RD2V
CVE: CVE-2021-47476

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ef143dc0c3defe56730ecd3a9de7b3e1d7e557c1



--------------------------------

commit 907767da upstream.

The driver uses endpoint-sized USB transfer buffers but had no sanity
checks on the sizes. This can lead to zero-size-pointer dereferences or
overflowed transfer buffers in ni6501_port_command() and
ni6501_counter_command() if a (malicious) device has smaller max-packet
sizes than expected (or when doing descriptor fuzz testing).

Add the missing sanity checks to probe().

Fixes: a03bb00e ("staging: comedi: add NI USB-6501 support")
Cc: stable@vger.kernel.org      # 3.18
Cc: Luca Ellero <luca.ellero@brickedbrain.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211027093529.30896-2-johan@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Cui GaoSheng <cuigaosheng1@huawei.com>