From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9C22DCD5BB1 for ; Mon, 25 May 2026 15:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KEioWnHBFrSVOzWNfEkI+OE/2Sc6ORJaNzdndpa/bQE=; b=NOJdRB1Q2UKah4QyMkOSH6N02s GYOC2tzJl1TxeMkt3/w36JD0MzlLDYWjzzQ8poauG2eH8vp8g/AhjdklgjDH3ulCLaEwB7DdTpeJc puv4OChVaHKLp56a2wVQ2Y7aTKcwYt3K4y1Mbn5VBChxs14n3kkH0B+SIm8gumS83+YzuTlB28Vbn +DTpZu6LhFjF990ccl0esoEQ2LE61W5dQRskrnU4/GrRBvn7aCvfnnyU6GfPYa1VEIihJfYuduF7O XNSVEENd4SPvRGu7W5J/zgdCGlAJ3lhNacNaKBybo+zJX4j6SmP5IFm33dHn/SC9Gslp9rCWQSgMH AY4fDioA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wRXCi-0000000HWCV-2Z2E; Mon, 25 May 2026 15:26:56 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wRXCh-0000000HWCJ-3ZFN for kexec@lists.infradead.org; Mon, 25 May 2026 15:26:55 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 0E97E600BB; Mon, 25 May 2026 15:26:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33C0E1F000E9; Mon, 25 May 2026 15:26:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779722814; bh=KEioWnHBFrSVOzWNfEkI+OE/2Sc6ORJaNzdndpa/bQE=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=RABhSdjt5u0xspCBftMJSAFcLnZnPAxEHcgKblhAtxk2MraxplpKc7uBljDlCqvPp zVTmMAHY2/KZRj0OAGoDXPHwZ+Nz/QC/QyXVkUoI3+bv01bgaAmOBagGDm/e+3tbEP jLCLsdybfirYpTfIb9IwBkU4e8p6QlLTxhuA+21yf/lM9yB9+6Xp9rflfRKcdut2K+ lGcvKjYnZgffXWdfk55VUWJGpgDn6MHoKiIEuplqxepYfj8mGRLipvfmd+VoUHNXbg 7lVlEA2UGcrQYxZpwhnGXh8LcxvUOIk8TDsf9KruXsGr8chSDyJ6nePwJzrUXnlhNJ bZcj708UaTX5w== From: Pratyush Yadav To: Yifei Chu Cc: Pasha Tatashin , Mike Rapoport , linux-kernel@vger.kernel.org, Pratyush Yadav , Andrew Morton , Alexander Graf , linux-mm@kvack.org, kexec@lists.infradead.org Subject: Re: [BUG] liveupdate: incoming/outgoing session ioctls accepted in wrong phase can panic In-Reply-To: (Yifei Chu's message of "Sun, 24 May 2026 10:44:31 -0400") References: Date: Mon, 25 May 2026 17:26:51 +0200 Message-ID: <2vxzjysr7bno.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Sun, May 24 2026, Yifei Chu wrote: > Hello, > > Short version: I found that liveupdate session ioctls can be accepted on the wrong kind of session. In my tests, that > lets userspace drive memfd LUO into KHO restore paths for current-kernel preserved memory, which hits kho_restore_page() > warnings and panics with panic_on_warn=1. I already sent a fix for this: https://lore.kernel.org/kexec/20260519122428.2378446-1-pratyush@kernel.org/ I need to do a refresh of this patch with some tests. -- Regards, Pratyush Yadav