From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from embla.dev.snart.me (embla.dev.snart.me [54.252.183.203]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C7EFD36827E for ; Thu, 30 Apr 2026 09:18:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.252.183.203 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777540686; cv=none; b=JBviDbyA8qP0167nJkjh+/5sbxZPwB9o9dmWEoSzHmC3VpOiy4Jc+IrNksaHm8Au8n6rQCic+osFVvXL3Oe4j+oGZc19aSquYBIDwYTtVYdaiTcVvhKKD/+NDaTmdTd6xE9W0JPyN4fN01KMYiO6h6KAlSdJF05Z51LdclNKCeo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777540686; c=relaxed/simple; bh=hpXLR5KnPpbI43DYCDcYx6+8S9SroRQrmJbGgrAvErI=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=dwCy8MDzeCn77G634S0qtN2xmhe2kNqb2rnPmwRx/arXUovDqFnK7TbidZxbkE8Kj+pZNpD74rR91BF2zLj82NQPLNR8rwC4WWjqiMnctV07N49zluSnCDNNEVzMqIqNYKKIZY9QQp444L06thXkVURSFIRIqzse2uf42G8Dqbc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=dev.snart.me; spf=pass smtp.mailfrom=dev.snart.me; arc=none smtp.client-ip=54.252.183.203 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=dev.snart.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dev.snart.me Received: from embla.dev.snart.me (localhost [IPv6:::1]) by embla.dev.snart.me (Postfix) with ESMTP id 82BD51D459; Thu, 30 Apr 2026 09:18:02 +0000 (UTC) Received: from [192.168.1.18] ([182.226.25.243]) by embla.dev.snart.me with ESMTPSA id 6sDXDEoe82nj4AUA8KYfjw (envelope-from ); Thu, 30 Apr 2026 09:18:02 +0000 Message-ID: <70c86ffd-b0ff-477f-965b-b144faf80f22@dev.snart.me> Date: Thu, 30 Apr 2026 18:17:56 +0900 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: David Timber Subject: Re: [PATCH v0 1/2] exfat: add volume limit bounds checks To: "Yuezhang.Mo@sony.com" , Namjae Jeon , Sungjong Seo Cc: "linux-fsdevel@vger.kernel.org" References: <20260429160824.409881-1-dxdt@dev.snart.me> Content-Language: en-US, ko Autocrypt: addr=dxdt@dev.snart.me; keydata= xjMEYmJg1hYJKwYBBAHaRw8BAQdAf5E+ri1XLtjqYbZdHOyc8oS+1/XJ5bSlbx5WHXmVBZzN IERhdmlkIFRpbWJlciA8ZHhkdEBkZXYuc25hcnQubWU+wpQEExYKADwWIQQn/Jn96EMUaIoF X+T/ldyyrZpWaAUCYmJg1gIbAwULCQgHAgMiAgEGFQoJCAsCBBYCAwECHgcCF4AACgkQ/5Xc sq2aVmjJZwD8COjPlUwccrlRvbNQ6f87DWchtYO0o8W2DNRM3RLps0EA/jEhIbRV6AsyC8jr 30Ut3aJ3/mO/6G4sLj7OvkEEBH0MzjgEYmJg1hIKKwYBBAGXVQEFAQEHQFpgtIgaByv9lIEY EmpavMO0pYjtu7TMJynwdnGYkN9LAwEIB8J4BBgWCgAgFiEEJ/yZ/ehDFGiKBV/k/5Xcsq2a VmgFAmJiYNYCGwwACgkQ/5Xcsq2aVmhFCwEA0kM9VyYB4bLCM7+SuXUUH+5Ec99Nj4RXxFad Key9GuwA/2BZK6bNyrLSfEk2JDRoskqf7OIL0wa6JOD5SrBnMe8E In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/30/26 16:52, Yuezhang.Mo@sony.com wrote: >> + /* Actually try reading the last sector to see if it's within the blockdev bounds */ >> + bh = sb_bread(sb, last_sector); >> + if (bh == NULL) { >> + exfat_err(sb, "last sector read failed : %lld", last_sector); >> + return -EIO; >> + } >> + brelse(bh); > Instead of checking by reading the last sector, we can use bdev_nr_sectors() to > get the actual size of the volume. Agreed. No need for exFAT to actually inspect the data at the last sector, unlike XFS. Monkey see, monkey doo.