From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="g0hf1x7x" Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB84410A for ; Mon, 27 Nov 2023 02:10:54 -0800 (PST) Received: by mail-ej1-x62a.google.com with SMTP id a640c23a62f3a-a00d5b0ec44so552074566b.0 for ; Mon, 27 Nov 2023 02:10:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1701079853; x=1701684653; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=pSRf/M0O+ZKi6iHJXEPlgfivAVZeJl23LnlZI/T7QFY=; b=g0hf1x7xJObHU1aQWZ78X1e1UT/hYcFntf2rpmUNJdtrdztsblv1M9AEOE7a2h3rHC 905ig6apmLFvsS6dGxIDJH8DqHD3OcgQA+gynfN1Uxj+6wZmNdkFLCXkhjrtasuAHT9k 2u9yS0W1z75q7+xMWDYvAi39/j0/IR8yc85Bx5ewptPGfTdxc74wK5FT9WMnhjCLJv0L 2goQSNpV9vo3CEVXD09ErGhOo0r3MXLUhwZrFzupVjWSJHORZSiAM3tv0u+An+cK9WBc 7yMobVf8ZvKmY2GEOubWXCDXOYsZJP3i8uL2ZYX0pl4lBlPkXv0hKkpDB6g4ZQpGhjvm lStQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701079853; x=1701684653; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=pSRf/M0O+ZKi6iHJXEPlgfivAVZeJl23LnlZI/T7QFY=; b=UJc6l0DrGXgYdfDR9I503AhKQUrLOn1TXTNsZ40cztX+WP1Sy8hsPfwQEm1NEYFvB7 HvjQwoL4RsBTvV+3oNCX6UrZ8k/bU3ZZl97x9dwgkxvxFUYHluZXE7L7zsjc0LG+hECt UDWZAoiXdX0Z00eMdSsirBuG7qeZyLFRX8p63zZ/MmSyFpYxE7JE2sHx8Zz00HXvB1BI uksamPWqPsCzmS8/c5YhyRst3FVDtttinwjXBiPp61QmGqo7adD5DJeSuRD40y3zmxjj EQB1/DfO4x6NwNiMwnftwGTjwLAvKOGgteu+NLIMDNfLI32X3Zu0sg/2LZBMBqw90byk KDnA== X-Gm-Message-State: AOJu0YyhnCLk21ynU/GtV+72ePtYLQHyudJPnfArRM6WP6mTE/8fbrju JxtOSsjp2+eXb5YbETvrgZyReg== X-Google-Smtp-Source: AGHT+IFeU+bqPm1OBmUwBspEGQL2vB9sgVK8SoOXZBuMexbZ4STkZzZ2VuiW8nBZf+zAgEW0rUZtlg== X-Received: by 2002:a17:906:2c4d:b0:9bf:b022:dc7 with SMTP id f13-20020a1709062c4d00b009bfb0220dc7mr7916810ejh.48.1701079853422; Mon, 27 Nov 2023 02:10:53 -0800 (PST) Received: from [192.168.1.20] ([178.197.223.109]) by smtp.gmail.com with ESMTPSA id bw24-20020a170906c1d800b009fc24437439sm5491621ejb.158.2023.11.27.02.10.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 27 Nov 2023 02:10:52 -0800 (PST) Message-ID: Date: Mon, 27 Nov 2023 11:10:51 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/4] nfc: Extract nfc_dev access from nfc_alloc_send_skb() into the callers Content-Language: en-US To: Siddh Raman Pant , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: From: Krzysztof Kozlowski Autocrypt: addr=krzysztof.kozlowski@linaro.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzTRLcnp5c3p0b2Yg S296bG93c2tpIDxrcnp5c3p0b2Yua296bG93c2tpQGxpbmFyby5vcmc+wsGUBBMBCgA+FiEE m9B+DgxR+NWWd7dUG5NDfTtBYpsFAmI+BxMCGwMFCRRfreEFCwkIBwIGFQoJCAsCBBYCAwEC HgECF4AACgkQG5NDfTtBYptgbhAAjAGunRoOTduBeC7V6GGOQMYIT5n3OuDSzG1oZyM4kyvO XeodvvYv49/ng473E8ZFhXfrre+c1olbr1A8pnz9vKVQs9JGVa6wwr/6ddH7/yvcaCQnHRPK mnXyP2BViBlyDWQ71UC3N12YCoHE2cVmfrn4JeyK/gHCvcW3hUW4i5rMd5M5WZAeiJj3rvYh v8WMKDJOtZFXxwaYGbvFJNDdvdTHc2x2fGaWwmXMJn2xs1ZyFAeHQvrp49mS6PBQZzcx0XL5 cU9ZjhzOZDn6Apv45/C/lUJvPc3lo/pr5cmlOvPq1AsP6/xRXsEFX/SdvdxJ8w9KtGaxdJuf rpzLQ8Ht+H0lY2On1duYhmro8WglOypHy+TusYrDEry2qDNlc/bApQKtd9uqyDZ+rx8bGxyY qBP6bvsQx5YACI4p8R0J43tSqWwJTP/R5oPRQW2O1Ye1DEcdeyzZfifrQz58aoZrVQq+innR aDwu8qDB5UgmMQ7cjDSeAQABdghq7pqrA4P8lkA7qTG+aw8Z21OoAyZdUNm8NWJoQy8m4nUP gmeeQPRc0vjp5JkYPgTqwf08cluqO6vQuYL2YmwVBIbO7cE7LNGkPDA3RYMu+zPY9UUi/ln5 dcKuEStFZ5eqVyqVoZ9eu3RTCGIXAHe1NcfcMT9HT0DPp3+ieTxFx6RjY3kYTGLOwU0EVUNc NAEQAM2StBhJERQvgPcbCzjokShn0cRA4q2SvCOvOXD+0KapXMRFE+/PZeDyfv4dEKuCqeh0 hihSHlaxTzg3TcqUu54w2xYskG8Fq5tg3gm4kh1Gvh1LijIXX99ABA8eHxOGmLPRIBkXHqJY oHtCvPc6sYKNM9xbp6I4yF56xVLmHGJ61KaWKf5KKWYgA9kfHufbja7qR0c6H79LIsiYqf92 H1HNq1WlQpu/fh4/XAAaV1axHFt/dY/2kU05tLMj8GjeQDz1fHas7augL4argt4e+jum3Nwt yupodQBxncKAUbzwKcDrPqUFmfRbJ7ARw8491xQHZDsP82JRj4cOJX32sBg8nO2N5OsFJOcd 5IE9v6qfllkZDAh1Rb1h6DFYq9dcdPAHl4zOj9EHq99/CpyccOh7SrtWDNFFknCmLpowhct9 5ZnlavBrDbOV0W47gO33WkXMFI4il4y1+Bv89979rVYn8aBohEgET41SpyQz7fMkcaZU+ok/ +HYjC/qfDxT7tjKXqBQEscVODaFicsUkjheOD4BfWEcVUqa+XdUEciwG/SgNyxBZepj41oVq FPSVE+Ni2tNrW/e16b8mgXNngHSnbsr6pAIXZH3qFW+4TKPMGZ2rZ6zITrMip+12jgw4mGjy 5y06JZvA02rZT2k9aa7i9dUUFggaanI09jNGbRA/ABEBAAHCwXwEGAEKACYCGwwWIQSb0H4O DFH41ZZ3t1Qbk0N9O0FimwUCYDzvagUJFF+UtgAKCRAbk0N9O0Fim9JzD/0auoGtUu4mgnna oEEpQEOjgT7l9TVuO3Qa/SeH+E0m55y5Fjpp6ZToc481za3xAcxK/BtIX5Wn1mQ6+szfrJQ6 59y2io437BeuWIRjQniSxHz1kgtFECiV30yHRgOoQlzUea7FgsnuWdstgfWi6LxstswEzxLZ Sj1EqpXYZE4uLjh6dW292sO+j4LEqPYr53hyV4I2LPmptPE9Rb9yCTAbSUlzgjiyyjuXhcwM qf3lzsm02y7Ooq+ERVKiJzlvLd9tSe4jRx6Z6LMXhB21fa5DGs/tHAcUF35hSJrvMJzPT/+u /oVmYDFZkbLlqs2XpWaVCo2jv8+iHxZZ9FL7F6AHFzqEFdqGnJQqmEApiRqH6b4jRBOgJ+cY qc+rJggwMQcJL9F+oDm3wX47nr6jIsEB5ZftdybIzpMZ5V9v45lUwmdnMrSzZVgC4jRGXzsU EViBQt2CopXtHtYfPAO5nAkIvKSNp3jmGxZw4aTc5xoAZBLo0OV+Ezo71pg3AYvq0a3/oGRG KQ06ztUMRrj8eVtpImjsWCd0bDWRaaR4vqhCHvAG9iWXZu4qh3ipie2Y0oSJygcZT7H3UZxq fyYKiqEmRuqsvv6dcbblD8ZLkz1EVZL6djImH5zc5x8qpVxlA0A0i23v5QvN00m6G9NFF0Le D2GYIS41Kv4Isx2dEFh+/Q== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 25/11/2023 21:26, Siddh Raman Pant wrote: > The only reason why nfc_dev was accessed inside nfc_alloc_send_skb() is > for getting the headroom and tailroom values. > > This can cause UAF to be reported from nfc_alloc_send_skb(), but the > callers are responsible for managing the device access, and thus the > UAF being reported, as the callers (like nfc_llcp_send_ui_frame()) may > repeatedly call this function, and this function will repeatedly try > to get the same headroom and tailroom values. I don't understand this sentence. "This can cause ..., but ...". But starts another clause which should be in contradictory to previous one. > > Thus, put the nfc_dev access responsibility on the callers and accept > the headroom and tailroom values directly. Is this a fix or improvement? If fix, is the UAF real? If so, you miss Fixes tag. Best regards, Krzysztof