From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792432726; b=hDtD3zvSVxhrHeGnBdlcT9ms1XCv5nIMeaXHa0RP0IWimwtlI0kuVHiTNF0tzHgjmcjp lD8v5Q1XxHg76OZAi6qOZDJUcnNN3uXkkdJmiRv9E/Otnh5mcc6ucitA8Kj5fb3I49jI0 79WJGC6EK9GZw5XqLHcl0+H5OH4gOaRjo/R4IFt0u325RLoD5z1HESKX0h4yUG+WMr4HE CUIMP9BdZ/nAsVu8635yjMDbKVoFPNIA4V9dakE1SJJX+QNu6z8Xi1CkTJQocS4XTh0Qo 1Gz1Q6JIyWanBHtO9bUTCyow9LpsF2Hbwh/L8veKZSFS2SOYBd7utiCV+3Tkl/12wbg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792432726; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-Id: In-Reply-To:References:X-Mailer:Mime-Version:Content-Type: Content-Transfer-Encoding; bh=oPj1wdj1uiPohgNU0SXZo753xMGMB0lBhXuRs/TA32Q=; b=TwA1fVlsDLdutl1gFQFHkzzWi+6tfDJSontNe+8wuSY7s9uTXLSW2ytUIbx4S2IfnNyQ 1NLvWOxcYLCY4UOM81ujSVFEpgH6qvBNv1mqwEUeDMAJJoFJzJut35DoEFytK8+YesCaP NyAGAZdPCgcofAfJAvLUEYNMxycQBdKVDfhi1puZmlO5FUvTt25vv7y/4g7FKfTjDpPho FCkKugQXOKlNZjxZMWYKre47b9cHFuatbOu3He6+imZbba0aMM0fg4SGieENl1plVY5gy orkokSUE+K6i1+q4Pcl4RyLVXPgV4ZwI6FdwCWPleMqhKJqxE57GbAbKdkAlsRxkuUQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=L+lRb7tg; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7683606A319 for ; Mon, 19 Oct 2026 17:58:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=L+lRb7tg Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC2901F000C4; Mon, 19 Oct 2026 17:58:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1792432725; bh=oPj1wdj1uiPohgNU0SXZo753xMGMB0lBhXuRs/TA32Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=L+lRb7tgu/5dsyOmtNeQsYQUgYNKPqVooCkrHEGDMjkgJ0nIp1gZ53JowXggaCgK9 jbspgOy7SIiuWTL/0cUBRj1CMIeDHzxtEh7Z/QV+swxfnuxuv3SLoHennW0zErr4jG P/U6x1Xu/oa4dK1kzkdhB9nySFbgXzUbjqYsqbn0= Date: Mon, 19 Oct 2026 10:58:44 -0700 From: Andrew Morton To: Yosry Ahmed Cc: Nikola Ciprich , Sean Christopherson , Borislav Petkov , David Laight , Rik van Riel , ljs@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, david@kernel.org, Mike Rapoport , Dave Hansen , Pedro Falcato , Kiryl Shutsemau , luizcap@redhat.com, pbonzini@redhat.com, Tal Zussman , Matt Fleming , gregkh@linuxfoundation.org, sashal@kernel.org Subject: Re: hunting memory corruption bug in 6.18.x Message-Id: <20261019105844.02d4623b7063fec25ebd34ad@linux-foundation.org> In-Reply-To: References: <20261014235736.GCatAW8GD0GlYumL4l@fat_crate.local> <20261015172820.7961d2c0def74d41cc6c4b0c@linux-foundation.org> <20261016031242.GDatGWKo98YSOhEOOn@fat_crate.local> <20261015211832.45d87fab15bb3e0bbc2f47cb@linux-foundation.org> <20261016054954.GEatG7AgMNFRkiTo1H@fat_crate.local> <20261018201538.d0957878f378a9821852836f@linux-foundation.org> <20261019083529.a81910ac0976c1a5687d4c6a@linux-foundation.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 19 Oct 2026 10:39:30 -0700 Yosry Ahmed wrote: > I am glad the commit fixed your problem! > > > > > Great, thanks. > > > > oops, we haven't been cc'ing Yosry. > > > > > Definitely a -stable candidate. Andrew, will you send it to Greg, or shall I? > > > > I volunteer Yosry or Sean ;) > > > > I think 55780d8a1dcc should be repackaged before sending over to the > > -stable people. Its changelog is very wrong: "The bug is benign > > though". Update the changelog to explain that the bug is in fact evil. > > Otherwise -stable and further downstream won't understand why we sent > > it to them and won't understand the impact. > > It was found through code inspection, there weren't any symptoms, and > I think I know why my analysis was incomplete. It assumes that > svm_recalc_instruction_intercepts() already ran at least once for L1 > (vmcb01) to configure its intercepts, which generally must be the case > (L1 must start L2), except during migration :') > > About repackaging, yeah we can add a note about the new finding and > the necessity of the backport. One question tho, is there a way to > send a patch to "all" stable branch (the same effect as adding Cc: > stable retroactively), or do I need to send separate backports to all > open stable branches? As far as I understand, a cc:stable and a Fixes: will result in it being backported into every tree which has the Fixes: target commit. > > > > And that repackaging would be an opportunity to add > > Reported-by:/Closes:/Tested-by: you, which is the least we can do to > > thank you for all this diligent work! > > Will do. Thanks.