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([2001:a61:1366:6801:d8:8490:cf1a:3274]) by smtp.gmail.com with ESMTPSA id u14-20020a05600c19ce00b004162bac1393sm2656197wmq.43.2024.04.11.08.40.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 11 Apr 2024 08:40:12 -0700 (PDT) Message-ID: Date: Thu, 11 Apr 2024 17:40:11 +0200 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC 1/6] usb: usb_parse_endpoint ignore reserved bits To: Alan Stern Cc: linux-usb@vger.kernel.org References: <20240411124722.17343-1-oneukum@suse.com> <20240411124722.17343-2-oneukum@suse.com> <3257a17c-cb38-4cc1-94ca-3e6dc4bb5d88@rowland.harvard.edu> Content-Language: en-US From: Oliver Neukum In-Reply-To: <3257a17c-cb38-4cc1-94ca-3e6dc4bb5d88@rowland.harvard.edu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11.04.24 17:35, Alan Stern wrote: > On Thu, Apr 11, 2024 at 02:42:59PM +0200, Oliver Neukum wrote: >> We have to ignore the higher bits in bEndpointAddress > > Mention that these bits are reserved. That's why we ought to ignore > them. OK > Also, this is not really an example of hardening; it's more like > future-proofing the code. The existing code will work fine with a > malicious device; your real concern is about possible changes to the > spec in the future. It seemed to me like a vector for a DoS, but in hindsight, yes I'll take it out of the series. Regards Oliver