USB: fix out-of-bounds in usb_set_configuration
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 19 Sep 2017 13:07:17 +0000 (15:07 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 19 Sep 2017 15:27:16 +0000 (17:27 +0200)
commitbd7a3fe770ebd8391d1c7d072ff88e9e76d063eb
tree7c3907fa163d0cf35761735ae3c6d8e59a9ee8cd
parentbcd6a7aa13800afc1418e6b29d944d882214939a
USB: fix out-of-bounds in usb_set_configuration

Andrey Konovalov reported a possible out-of-bounds problem for a USB interface
association descriptor.  He writes:
It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION
descriptor. It's only checked that the size is >= 2 in
usb_parse_configuration(), so find_iad() might do out-of-bounds access
to intf_assoc->bInterfaceCount.

And he's right, we don't check for crazy descriptors of this type very well, so
resolve this problem.  Yet another issue found by syzkaller...

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/config.c
include/uapi/linux/usb/ch9.h