On Mon, Jul 3, 2023, at 14:45, Greg Kroah-Hartman wrote:
> On Mon, Jul 03, 2023 at 02:30:32PM +0200, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@xxxxxxxx>
>>
>> __ffs_func_bind_do_os_desc() copies both the CompatibleID and SubCompatibleID
>> fields of the usb_ext_compat_desc structure into an array, which triggers
>> a warning in the fortified memcpy():
>>
>> In file included from drivers/usb/gadget/function/f_fs.c:17:
>> In file included from include/linux/string.h:254:
>> include/linux/fortify-string.h:592:4: error: call to '__read_overflow2_field' declared with 'warning' attribute: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror,-Wattribute-warning]
>> __read_overflow2_field(q_size_field, size);
>>
>> Usually we can avoid this by using a struct_group() inside of the structure
>> definition, but this might cause problems in userspace since it is in a uapi
>> header.
>
> We use this in other uapi .h files, what is unique about these fields
> that makes it so that they can not be used? Because it's not the last
> field?
It's probably ok, and I was overly cautious. I'll send a new version after
some more testing.
Arnd
