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X-CSE-ConnectionGUID: Q6SlUH+PR+6VSSnSTABKFA== X-CSE-MsgGUID: owfcDeh5RKupe5eGHnwUBQ== X-IronPort-AV: E=McAfee;i="6700,10204,11314"; a="40974514" X-IronPort-AV: E=Sophos;i="6.12,310,1728975600"; d="scan'208";a="40974514" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Feb 2025 15:16:16 -0800 X-CSE-ConnectionGUID: Ic7EysGdQW64EyjdROkCZA== X-CSE-MsgGUID: 2BWnipDbRPaqhqV2HSR8aQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,299,1732608000"; d="scan'208";a="115057454" Received: from kinlongk-mobl1.amr.corp.intel.com (HELO [10.125.109.250]) ([10.125.109.250]) by fmviesa008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Feb 2025 15:16:14 -0800 Message-ID: <5007ae91-f4d5-430b-a403-aff9af1d6375@intel.com> Date: Wed, 19 Feb 2025 15:16:14 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/1] kexec_core: Accept unaccepted kexec segments' destination addresses To: Yan Zhao , ebiederm@xmission.com Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, x86@kernel.org, rick.p.edgecombe@intel.com, kirill.shutemov@linux.intel.com, bhe@redhat.com, Andrew Morton , Baoquan He References: <20241213094930.748-1-yan.y.zhao@intel.com> <20241213095449.881-1-yan.y.zhao@intel.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/13/24 01:54, Yan Zhao wrote: > Accept the destination addresses during the kexec load, immediately after > they pass sanity checks. This ensures the code is located in a common place > shared by both the kexec_load and kexec_file_load system calls. So, we've got an end-user-visible bug. Eric raised some good concerns about the hardware and firmware design, but I think they've all been addressed. The only other even solution I've seen proposed is to not do unaccepted memory in the first place. I don't think that's viable or justified, especially since we've got at least one end user[1] that seems to think unaccepted memory fits their needs. This bug can _probably_ be fixed in arch/x86 as well, but having the solution in general code seems like the right place to me: Acked-by: Dave Hansen Andrew, it seems like a lot of kexec work flows through you. Are you the right one to pick this up? 1. https://lore.kernel.org/all/CAMGD6P3r-S-Va-TRvVjZ808on9+-wFJ_VeTpQ+FEN1jBbhmnXw@mail.gmail.com/