From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A8C1A1E7C1C; Wed, 13 Aug 2025 07:09:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755068998; cv=none; b=Tj1BXlIcG/hf4BVXYgeM5zSyxDrIaRuoax0zfVJkg2g6SAtVmyXLhcY/Cv4bKoY0yb0OkEY4Pih1Uu2r4mCA53cOHosTzv1z7pSNZo4VYaXhotkyJPr/j3SqClf50oFxz/8VRF69E0gQFOmoQN4MLkmW9dgrZ8b15wDcg9DnhX4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755068998; c=relaxed/simple; bh=qYxBarsfIxoqtVOdgyZu0XSkWfI2wWyZlaofZIWXx50=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=caIPPPPCqirBX9piD6ZjZYTWZJG2cpxb0oxBHzIQXLeoiQxSWFGXc8svuUfusMkbY6lqXJxlC8gbdOkdu+BZpm3sGb8iUWnKVSPEUUirnifE43/n9UB7dw8WfXvchxUzFxs7cY1tyscQoTOaasL4K4WInH/RGVJE2TSFyrhX5jQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NocSEfYL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NocSEfYL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA26AC4CEEB; Wed, 13 Aug 2025 07:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755068998; bh=qYxBarsfIxoqtVOdgyZu0XSkWfI2wWyZlaofZIWXx50=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NocSEfYLe30ZRY2fHD2eMr9WqjHVuC9F/px//tLPS15SsrzoG9iv1HwM8iQDKE67S ZqIZrwB6jm/9KKfam0/4WZbDHX0t5+hxCiBriTSU8w8f0hqWmVGvbCFp0w4JQSDEvS 7dYDYI0kpYCmumRuzXCuANSWpidAV9iKz8KGjkmU= Date: Wed, 13 Aug 2025 09:09:54 +0200 From: Greg KH To: Vipin Sharma Cc: Pasha Tatashin , pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, changyuanl@google.com, rppt@kernel.org, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, jgg@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com Subject: Re: [PATCH v3 29/30] luo: allow preserving memfd Message-ID: <2025081310-custodian-ashamed-3104@gregkh> References: <20250807014442.3829950-1-pasha.tatashin@soleen.com> <20250807014442.3829950-30-pasha.tatashin@soleen.com> <20250813063407.GA3182745.vipinsh@google.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250813063407.GA3182745.vipinsh@google.com> On Tue, Aug 12, 2025 at 11:34:37PM -0700, Vipin Sharma wrote: > On 2025-08-07 01:44:35, Pasha Tatashin wrote: > > From: Pratyush Yadav > > +static void memfd_luo_unpreserve_folios(const struct memfd_luo_preserved_folio *pfolios, > > + unsigned int nr_folios) > > +{ > > + unsigned int i; > > + > > + for (i = 0; i < nr_folios; i++) { > > + const struct memfd_luo_preserved_folio *pfolio = &pfolios[i]; > > + struct folio *folio; > > + > > + if (!pfolio->foliodesc) > > + continue; > > + > > + folio = pfn_folio(PRESERVED_FOLIO_PFN(pfolio->foliodesc)); > > + > > + kho_unpreserve_folio(folio); > > This one is missing WARN_ON_ONCE() similar to the one in > memfd_luo_preserve_folios(). So you really want to cause a machine to reboot and get a CVE issued for this, if it could be triggered? That's bold :) Please don't. If that can happen, handle the issue and move on, don't crash boxes. thanks, greg k-h