Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] HID: Extend report buffer size
To:     Alan Stern <stern@rowland.harvard.edu>,
        Johan Korsnes <jkorsnes@cisco.com>
CC:     Jiri Kosina <jikos@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kernel development list <linux-kernel@vger.kernel.org>,
        <stable@vger.kernel.org>
References: <Pine.LNX.4.44L0.2002100957401.14460-100000@netrider.rowland.org>
From:   peter enderborg <peter.enderborg@sony.com>
Message-ID: <91e0077e-b229-e43f-6f5c-5088b0c0f561@sony.com>
Date:   Tue, 11 Feb 2020 09:35:02 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.9.0
MIME-Version: 1.0
In-Reply-To: <Pine.LNX.4.44L0.2002100957401.14460-100000@netrider.rowland.org>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Language: en-GB
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 2/10/20 4:01 PM, Alan Stern wrote:
> On Mon, 10 Feb 2020, Peter Enderborg wrote:
>
>> In the patch "HID: Fix slab-out-of-bounds read in hid_field_extract"
>> there added a check for buffer overruns. This made Elgato StreamDeck
>> to fail. This patch extend the buffer to 8192 to solve this. It also
>> adds a print of the requested length if it fails on this test.
>>
>> Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
>> ---
>>  drivers/hid/hid-core.c | 2 +-
>>  include/linux/hid.h    | 2 +-
>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
>> index 851fe54ea59e..28841219b3d2 100644
>> --- a/drivers/hid/hid-core.c
>> +++ b/drivers/hid/hid-core.c
>> @@ -290,7 +290,7 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
>>  
>>  	/* Total size check: Allow for possible report index byte */
>>  	if (report->size > (HID_MAX_BUFFER_SIZE - 1) << 3) {
>> -		hid_err(parser->device, "report is too long\n");
>> +		hid_err(parser->device, "report is too long (%d)\n", report->size);
>>  		return -1;
>>  	}
>>  
>> diff --git a/include/linux/hid.h b/include/linux/hid.h
>> index cd41f209043f..875f71132b14 100644
>> --- a/include/linux/hid.h
>> +++ b/include/linux/hid.h
>> @@ -492,7 +492,7 @@ struct hid_report_enum {
>>  };
>>  
>>  #define HID_MIN_BUFFER_SIZE	64		/* make sure there is at least a packet size of space */
>> -#define HID_MAX_BUFFER_SIZE	4096		/* 4kb */
>> +#define HID_MAX_BUFFER_SIZE	8192		/* 8kb */
>>  #define HID_CONTROL_FIFO_SIZE	256		/* to init devices with >100 reports */
>>  #define HID_OUTPUT_FIFO_SIZE	64
> The second part of this patch is identical to the "HID: core: increase
> HID report buffer size to 8KiB" patch submitted by Johan Korsnes a few
> weeks ago.  You might want to submit just the first part of your patch,
> or not submit anything at all.
>
> Alan Stern
>
>
Korsnes patch is not in Torvalds tree nor is it requested for stable. How do we get it there?