Re: [PATCH] HID: tighten ioctl command parsing

[Arnd Bergmann]

On Thu, Aug 21, 2025, at 08:56, Benjamin Tissoires wrote:
> On Jul 11 2025, Arnd Bergmann wrote:
>>
>> +			break;
>> +	}
>>  
>> +	hid = dev->hid;
>> +	switch (cmd & ~IOCSIZE_MASK) {
>
> Jiri pinged me about this one, and I gave it a go with the existing
> tests I have in selftests... and turns out that this changes the logic
> of the ioctl processing.
>
> The removed block was in the default section of the switch/case
> statement. Now it's added *after*, meaning that any ioctl that was
> normally processed before are now caught in the default of the switch
> statement below and return -ENOTTY.
>
> Running tools/testing/selftests/hid/hid_bpf showed that.

Ah, of course, thanks for checking and describing the issue.

Did you already come up with a fixed patch? I'm currently
travelling and won't be able to send a v2 quickly, so if you
have a version that works for you, let's use that instead.

     Arnd