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 6CB7B4F7CA5; Thu, 17 Sep 2026 16:35:43 +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=1789662944; cv=none; b=foO+pKwEMii8leHRZuc56+Zow2TWZcOgOdJ80dXt39JZAgzVZmeG4D6Q5Uzj8OP+VWetoZRbPwCM7+O4HQKJ0xXKaeC3m9NcrUmaj1lQN6SlE5RWqhTnJDT3qQlkYGkK+0gT4/ct/V19TBIouWtar2JekKzPg2vzMyHfd5R1yOI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662944; c=relaxed/simple; bh=srNzKq7fofHttIELlvlJ1JXyChSF0gnbXxhEM58NSes=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IPqC9fZQ5dCuvFNpbMNFcy0PYicO5ohQAvANo9Gl0MBOLYkQxZzLrvnVUm5P7v6PXRYlnh4vO30Qi7PFhnMGcY2RzgQnI5dL7/iBD4UWG+OhRhGvrdXKGQGhGJJPK4eb7mdNSNesD+NShiMrj1KQMNGL9BQhDbIieDT+aJ5Ia7I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IV/9Pasm; 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="IV/9Pasm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74F111F000FF; Thu, 17 Sep 2026 16:35:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789662943; bh=FKVFt5hWEYnD6eEg5v/Xa2EXI6qsPR+4lUqezNWfIlU=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=IV/9PasmZBO5YhUTKMJwtqWrDzyfIMqG98/OixkibqYaETeveCJSocgYxeinKbgWe MpmlWpxjyxZJirkQc6IvLeLnsl5k9Qb+FABl8TpZTDl4IGbNImcxeUx5LkBJjyyy/S dfOTQHdnOzZ8R3RoG/CXK5ZNSnSORxfdCu4tIg2CmJ2rQ9UMzfBgGYbpWkmXlqTlvc ZFzojg34izQY/BkB0N5UslgtRdnFDJs6wKXp4YB2TTlkgKCQF+IyEV0DKTQdyp/TA7 b5Cyfq4c/U04mWPjwEyiBhs4nTJGz5z5iWZy9wy/4BbexSb2mlB8sm0LG9LLYHs4gr JlWWa9qVTrEBg== From: "Lorenzo Stoakes (ARM)" Date: Thu, 17 Sep 2026 17:22:34 +0100 Subject: [PATCH v3 25/40] mm/vma: enforce that only kernel-owned mappings may set VMA_IO_BIT Precedence: bulk X-Mailing-List: linux-fbdev@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: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-25-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@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 , Chengming Zhou , Michal Hocko , Miklos Szeredi , Xu Xin 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=srNzKq7fofHttIELlvlJ1JXyChSF0gnbXxhEM58NSes=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLLWCB+qe5lUeSZ0do9k1ofr3R5LajbFpLa2dWjl3N4yK 5PxSUtuRykLgxgXg6yYIsvzL+L7g0TC5nVe8HeDmcPKBDKEgYtTACayvpKR4b6RTVDOs/tZHw76 Pf4btYWFM3zlM/kZ4bVfDzxa7RzldIfhf+LPwCkBHut65XITpNiSFkr3rdWy/jLz0OrUifvY79V fZAcA 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 1db8b218fe64..56a0cd154419 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -2787,6 +2787,12 @@ 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