From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail05.groups.io (mail05.groups.io [45.79.224.7]) by spool.mail.gandi.net (Postfix) with ESMTPS id C6294740038 for ; Sat, 20 Apr 2024 16:31:58 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=FDJztfsjLnniXWwTQAZ8hcZ4rdJqI5XzYuLj6E07+tM=; c=relaxed/simple; d=groups.io; h=Message-ID:Date:MIME-Version:User-Agent:Subject:To:References:From:Autocrypt:In-Reply-To:Feedback-ID:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Resent-Date:Resent-From:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Language:Content-Type:Content-Transfer-Encoding; s=20240206; t=1713630717; v=1; b=HBdnFQOsrVE9zxyHV03zZ4YXmE/ACTIJvDqsnk4HAwF++J4qMfrB/XDhtYTkiUHY/Hu7TwxA gpmlEcrpbuBe81RIE8cKcQtlBr+fXfuOLQMGiv1alm+hx2JobdB4cvHowx8Dzkxhp4xBiZu5EYl f3OWXFkS1zwp/azcE8DM52ozMlei7zcht7H4tpsAMoqmfDKNnqT1S+WDbQeMVXNyvMfmSqEDP4O RuBTWNduoH/X5VxtggtIZkE2uT+LXKWkwsNnjkppW19c0VUUGd8ZkogHlpX/RAc6rlFUYAnQlpb DF28hbtkZ5ypfRLqPKiMxaBlEjq6qyD341l7YwU7RVnsQ== X-Received: by 127.0.0.2 with SMTP id j6MxYY7687511xpRjvYQWX6B; Sat, 20 Apr 2024 09:31:57 -0700 X-Received: from a7-19.smtp-out.eu-west-1.amazonses.com (a7-19.smtp-out.eu-west-1.amazonses.com [54.240.7.19]) by mx.groups.io with SMTP id smtpd.web11.15452.1713630715773135162 for ; Sat, 20 Apr 2024 09:31:56 -0700 Message-ID: <0102018efc599893-f6eb6958-4674-49ce-9909-0a5e52b950d7-000000@eu-west-1.amazonses.com> Date: Sat, 20 Apr 2024 16:31:54 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [edk2-devel] [PATCH] NetworkPkg/HttpBootDxe: Correctly uninstall HttpBootCallbackProtocol To: devel@edk2.groups.io, mjsbeaton@gmail.com References: <0102018eb46489d7-9d4baa6c-98e6-4ef5-a477-1beeb1980005-000000@eu-west-1.amazonses.com> <2759.1713520973467563953@groups.io> From: "Michael Brown" Autocrypt: addr=mcb30@ipxe.org; keydata= xsFNBGPmfF4BEAC3vcU4aLC/9Uy/rTpmYujbqxQNZje9E34jGvLxO3uYwj4BeHj1Nn5T2TDM Gkc4ngk+mGPsJsIn69YU5cfVN+ch9O7FVfsn6egZsCNeLy6Qz0o//gBaWJodFBeawuBjXXyV HnQZa1p7bA/Lws8minW7NrZ7XZgEBaiVm1v1dNbLEoWR8UL2AMtph5loCQ5jPYQNqp/wH9El /R30GjXvAd1riWyJR2TWSN23J9rnuH2Ue+N4yEnWxAsBQ6M/NFQ5z42w4mYdsnzy1w3PulrL icpSixXHkm3lQcKGtKKX41HvJukSpxCgbHfuHGEJZ7bdhgRic1DHKav0JR8kQhx3gnPh06z8 1Teu2NKkSsTR3Iv6E2x6Yy6H34lKWzBzd8TLNSevesDD/L6NU/HxT9AxrTBuypk9PZGe2VH1 W03XnR/0Mnr0QqQBXcIAERdgNzRJY4VKF75vedf8IooZFUQ4RUlqH+x3aZB9nJ9ET77mPaNi SQVQBxE68uzb7eh2Kf6z7ftOYpWPw1v5HyB3oMmafEDG36SIvNF2wnmNaLQDRnAbTcy4ERgy tpJ3wtQDJeXOePLv8hJ3q7DSuePl7cwz4xy0ZHglW/EXRXLnyRRACfDGowyENoStg06qF+qm edGu1wNtmDZ/lypWm/CkzzpUDFeGP5BLZlqwVX4hn88llfvVzwARAQABzR5NaWNoYWVsIEJy b3duIDxtY2IzMEBpcHhlLm9yZz7CwZEEEwEIADsWIQTgD69MBpjBm2slMvwCNbEKAOtEUAUC Y+Z8nwIbAwULCQgHAgIiAgYVCgkICwIEFgIDAQIeBwIXgAAKCRACNbEKAOtEUFlhD/9ElIUg JxBXpIbF8s7u79OdXLld2Z1DfVmhP5Q+GilPvEeAWHhp689S9B88aNvpwW5zJfxlxcJZO0ay jc7E/vtdNrkXGWNEEXBgdve6m+uL+pW/i5E2htqxbLyfgTJKmsvJ8graHbwrrBS/PA8KuwVJ eAGbBNi3f1gyQQWrLqfTkUpLtuj7A76iVVk0G0a78L69Al84qhK2imqpFJoZt1F8h0Z5ddGv mvf2M/DZp87UXvXjy7X6r7msbMZa6S/Jv0dtWHeZGl3Xu3qzbtjlqFyz2Q7TibHiirsgg/CV BsbH/LLbi/aNCCQ/85C6jAMB0lNzcVZ7ZiKKo+vBNMTycDFk70LA9yjlNf7exHejoXmPkLmH ddapYZ4dzwdOiJlaTu8NZgzXUCt3RDDA1qmZrAOBF/F+tPILAEhenl9kj3blD3mPV2SrWLWY dbahY9BsylUhj/qE1ik5CJXrPotmJhok9Vpg07xKDpVnZXuWLGNIE8018UumO7phLrWQwLb1 wJdN7PG165w4UWf4aQphfwaMKOVU3WDghz3aVSP9rgtm3RsUcYHPKx8IaPcDh2yf0bgG386i Axx3U3UQeyz2Pb9Vigo6DmPwXjLkFr/dukvVLVJLVkUab9ZhhERzWTEEMifUVEK2rGNvA87L VKJ2zOyxWx1e0CPj6fcGbkJ0D10XLs7BTQRj5nxeARAAz18zv2ksRiM6eEKG0qzpiKHVYlVy wtjla+m9wuAIwm314tffY5hjQN46uwTstdhQirjywF1EmcS6KNGiIjmoLim+dqyFP5d/UF5A VjLt0TYq7HjadIxbm2/CvcRnNJ01FkD99xLxV0hFTUAWAUX1mNqQ3MmWIjV89wiT06uuAUog m+jG3RRDyWbUnVELR60mhzccKsaEsjO/HqIERvBwL7tlOJewlPrVyz9Zed9Nhhv0KDAYmdEm kIEEbOfsjRu5I6nIY3NrX+QP9+nmgxADlsjvLXTSU0fT/g7IPEl3gpsQZAbgmrlGcPtvXod8 P4iOmL8GJDU1RdBE9TBOLEbu9UlDRD4zr6tdzRpB9wvXdtSUcNCdHVqJTfq2qjIlBk7x+zQD ayhxzDvTMxD/93K6txKXmVVtfMBsmt9KuD2JBUEAExjsLHqzg48nQg8wF9JYWCWGBb36qpd0 yC6VPzhSLe2Ov3/GyV5ZshO046+OiGxEeaHCwMnDTZF9xrQ5paCwWedlWKvGM2zB64AHuk+M v2ABK/gbDO7eS6p+xz11oD1NHr1HQLRtknfClIqj9AmjgX9maD+4GUrmHaxmkNilIukahotd Un9Up2gX05Wy/S3H/v8RB0kxwWg2Wh065dnyCF4Doe18bcYZvM+iMJmUBag6aDfQlryM04K7 z4ITYDkAEQEAAcLBdgQYAQgAIBYhBOAPr0wGmMGbayUy/AI1sQoA60RQBQJj5nxeAhsMAAoJ EAI1sQoA60RQZj4QAIkiRDVNWynZ4kEdpqmf6hpD++Zycz+LMne4iGRsiyyTf/rPNgskNLrU JD555yDvFiEAhOI27R8YNCJj5byXRDa/Bm6ueClFia+POibt28UEdyOFU9PVcgFaU+VxaBIP rHacHL6A7UKFjmBN7o8VkVF2xXlmFge795mP4/Y3t6qfWUTodrpw1w1t5/bZxZdWqX4pUCpY fEx87jm60+Mj0Tb4VPWXz0UD1q1BDcdYxNa2ISLaJhGJmjjks9eqdFOhPo1fTINMNWF2Alxi jA6WNT8nn9lm1kav75EMYMc8WIR9tb03i+IuKNp2IWwTGBqIUyQj00BhHkZQFl4HxZhV0gXE AWu34Q/Z7hOUXGXq2tvYCxDeaQb2wks93e62lrrUm1JGhPWkVoCI8Md8N2mkonqIfMK8lQ0W WbkYHdKBkgDqhDypNNhkjWNX3JL1kL0c3rqGL381iBAZaGQPygyCx2xH9PDNp59W6u8sXb13 +UX+kXdWU+KYbMTVoO/t4MxUJg6nXPJHz9NCkyluI820l+2OtXZZy0u196evIlUdD6RoTrNK z5OgFxNctVi9BPsQea9du+JlYJ460vZNPz180oczj7iqffd+p9DmAkeK25njWhg3qPeXiNZN 45J9eMChSOaJ0GMGUQndIIxz7PO8IzjbkSHLG5CKrR3MaphMB/0L In-Reply-To: <2759.1713520973467563953@groups.io> X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on blyat.fensystems.co.uk Feedback-ID: 1.eu-west-1.fspj4M/5bzJ9NLRzJP0PaxRwxrpZqiDQJ1IF94CF2TA=:AmazonSES X-SES-Outgoing: 2024.04.20-54.240.7.19 Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Resent-Date: Sat, 20 Apr 2024 09:31:56 -0700 Resent-From: mcb30@ipxe.org Reply-To: devel@edk2.groups.io,mcb30@ipxe.org List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: X-Gm-Message-State: iWyEUtKlo3OCO2X8dwpjFxVFx7686176AA= Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20240206 header.b=HBdnFQOs; dmarc=none; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 45.79.224.7 as permitted sender) smtp.mailfrom=bounce@groups.io On 19/04/2024 11:02, Mike Beaton wrote: > Dear Michael, > > I don't know if you had time to answer one follow-up question. > > Obviously one thing that someone might want to do is to notify on > protocol installs and trap installs of this protocol - e.g. so that > something other than UefiBootManagerLib can manage and monitor HTTP > boot, but still allowing the original callback to occur, by hooking it. > Not sure if this counts as 'supported' or not (possibly not...) though I > think it may count as 'quite likely to happen'. However, one could hook > in such a way that the uninstall would succeed anyway, assuming that the > function pointer within the original installed protocol is writeable. > > My question is: was the above is roughly what you were thinking of, that > might cause the assert to fail, or, if not, if you had the time to give > a very brief sketch of what else it might be (just a plausible, very > rough example)? Certainly not saying you're wrong, just that it would be > helpful (to me!) to understand what sort of thing you were thinking of! I don't have a specific use case in mind for why someone might want to have opened this particular protocol in a way that would subsequently cause UninstallMultipleProtocolInterfaces() to fail (e.g. opening with BY_CHILD_CONTROLLER attributes). Just that, as a general rule, there exists a design flaw in the UEFI specification that means that operations that should have been chosen at the design stage to be conceptually impossible to fail (such as freeing memory or uninstalling protocols) are instead allowed to return a failure status. This design issue manifests itself as extremely unreliable behaviour on the removal or shutdown paths of many UEFI drivers. For example: many drivers will simply deadlock the system if disconnected from their underlying controllers (e.g. via the UEFI shell "disconnect" command). In the case of UninstallMultipleProtocolInterfaces(), the failure mode is particularly problematic since the specification dictates that the firmware must do the absolutely worst thing possible by *reinstalling* any protocol instances that it had managed to uninstall, and consequently retriggering driver Start() method calls. This generally leads to chaos and confusion (and use-after-free bugs that could probably be fairly easily extended to obtain a Secure Boot exploit). There's nothing that you really need to do specifically in HttpBootDxe to work around this design flaw. But it's definitely worth removing the unjustified ASSERT(), since that ASSERT() may cause a crash in a system that could otherwise continue to operate successfully. Hope that helps, Michael -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#118048): https://edk2.groups.io/g/devel/message/118048 Mute This Topic: https://groups.io/mt/105368366/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=-=-=-=-=-=-=-=-=-=-=-