USB: fix out-of-bounds in usb_set_configuration
commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h
index a8acc24..5e64a86 100644
--- a/include/uapi/linux/usb/ch9.h
+++ b/include/uapi/linux/usb/ch9.h
@@ -759,6 +759,7 @@
__u8 iFunction;
} __attribute__ ((packed));
+#define USB_DT_INTERFACE_ASSOCIATION_SIZE 8
/*-------------------------------------------------------------------------*/