From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 68B775A512C; Tue, 8 Sep 2026 20:13:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788898434; cv=none; b=j23uVm4FmNJHchBF7P9aLYrJb/vOX4s1j9cCNTtYU5hifBVwUzCc7/SZknjEKvg2Rhtc6PjiQF/3V4zXuuDNKXRYoqdWHKFNWbSTWfrfUeFMZ4PPp5OzHNPXAVD8f4cHrqLOIRA0o7BMS9Wl9YkC2YP6bsZHcw5Ra+0BspJuiJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788898434; c=relaxed/simple; bh=Waz7DiD3rguBJppiiScbshRu8gUGaEpIlzQeObU8kmI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Vk2OZkuJjry4pqMxNbSfIzXV4+dbliZJlPtRSu565K8m/QYdN1NSPqBqxXND8+A7CuUaKTom8AUr/Hk4R4Sm6O0RabepI7ZWxQ6OqWb+d01o5Tu3ALdM+0IWMT3NLQ5O4dgdOdmL/VWYAkCEb+agHv4grvUb2lFwuosYAjOydHQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f+Mr+LZ5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="f+Mr+LZ5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 041C11F00A3D; Tue, 8 Sep 2026 20:13:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788898433; bh=zxsoHiZuiEmxcJzcWN4k6DuzJHqi17MQRpDsUiD+p6A=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=f+Mr+LZ58EWjR1Vj2Y5dhsxFsGCZxc+h1J3z0LW/Dz9YFUtW31pXWkPAuPHaQLwT6 XID45ZVviQp1sn4ZyDvfZC0qj8TiV4MhitcrJ5xl4HyXLD4mbiHsILxVcHNJu1r1eF +IgSffXPhD1650r0HHbohuhzizR6waCzyazMS2u9ne16fJavkbA8xOgfWVIY7CLOev +CXWw8pxxuoSNswby4MLsIWIbEgAVKt0RocXC7OHhsVYfUZSss/lLjIkmorwpW+XTm XGAivUcLQSspqcjTNjKulBCyAjPHqAYEL4W5mIN09vBk00oewkoopdDJb/9JVzsb8j wR2ZUYVjlTEEQ== From: "Lorenzo Stoakes (ARM)" Date: Tue, 08 Sep 2026 21:01:28 +0100 Subject: [PATCH 24/39] mm/vma: enforce that only kernel-owned mappings may set VMA_IO_BIT Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-24-dacf19cce22b@kernel.org> References: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> In-Reply-To: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> To: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , David Hildenbrand , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Greg Kroah-Hartman , Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Paul Moore , Stephen Smalley , Jaroslav Kysela , Takashi Iwai , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Doug Gilbert , "James E.J. Bottomley" , "Martin K. Petersen" , Jaya Kumar , Simona Vetter , Helge Deller , Sebastian Reichel , John Hubbard , Peter Xu , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Rik van Riel , Harry Yoo , Juri Lelli , Vincent Guittot , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Arnd Bergmann , Muchun Song , Oscar Salvador , "Matthew Wilcox (Oracle)" , Jan Kara , Marc Zyngier , Oliver Upton , Catalin Marinas , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , "David S. Miller" , Andreas Larsson , Alexander Viro , Christian Brauner , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Youngjun Park , Johannes Weiner , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Xu Xin , Chengming Zhou , Michal Hocko , Miklos Szeredi Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-usb@vger.kernel.org, linux-rdma@vger.kernel.org, selinux@vger.kernel.org, linux-sound@vger.kernel.org, bpf@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, fuse-devel@lists.linux.dev, "Lorenzo Stoakes (ARM)" X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=988; i=ljs@kernel.org; h=from:subject:message-id; bh=Waz7DiD3rguBJppiiScbshRu8gUGaEpIlzQeObU8kmI=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLIWZG6xdK1TKJ/+t6vvAO+7/4wPmDUiFX991cpqLJkr4 rrsxsr3HaUsDGJcDLJiiizPv4jvDxIJm9d5wd8NZg4rE8gQBi5OAZjIrl+MDGuZw/32qyX85TdQ 2J3TPqvM223zrmdpi5nrqw3n2xX8/MDwPyZeaV/9mzmlK9K3p066/oSRYfW007c8v/9Ivea/xOh KCjcA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 It makes no sense for a mapping whose contents the kernel does not own to specify that the range is MMIO. Prior to this patch, all in-tree drivers which did so have been updated such that they are marked as kernel-owned. The check WARNs and fails the mmap for any out-of-tree driver that still sets VMA_IO_BIT without a kernel mapping. No functional change intended for in-tree code. Signed-off-by: Lorenzo Stoakes (ARM) --- mm/vma.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/vma.c b/mm/vma.c index cb0c4c625756..5996757d5aaf 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -2772,6 +2772,12 @@ static int mmap_validate_vma_flags(const vma_flags_t *flags) return -EINVAL; #endif + if (!vma_flags_test_any(flags, VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT)) { + /* Only kernel-owned mappings may set VMA_IO_BIT. */ + if (WARN_ON_ONCE(vma_flags_test(flags, VMA_IO_BIT))) + return -EINVAL; + } + return 0; } -- 2.55.0