This from static analysis. The vla_item() takes a size and adds it to
the total. It has a built in integer overflow check so if it encounters
an integer overflow anywhere then it records the total as SIZE_MAX.
However there is an issue here because the "lang_count*(needed_count+1)"
multiplication can overflow. Technically the "lang_count + 1" addition
could overflow too, but that would be detected and is harmless. Fix
both using the new size_add() and size_mul() functions.
Fixes: e6f3862fa1 ("usb: gadget: FunctionFS: Remove VLAIS usage from gadget code")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YxDI3lMYomE7WCjn@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>