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 2414C4DEC3C; Thu, 17 Sep 2026 16:33:41 +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=1789662822; cv=none; b=RIadkphV4FyrGDrR9ERJeIXINxgFFIr8MrG2V3g6eqR5xxnMY4vVurMj1dEGAlRRDcd95j9A3JyrxF5ek9Xa0P8m32tnDvOQ28fuzUpkom7x4JEBe5KuVQjAsu4ya7nFJFPb+ZXQ0Jlk4cj7zFZGe8FD8g4tYmO2US3rJu0KEyA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789662822; c=relaxed/simple; bh=NwkWQQ7fmwzL5QGJDJ/xCgQWUhs8DQGRd4wM7Vj8ofA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ZTN/biBZHtOmhkODtLXCgWCm8DA+N3lqVY80vLhc0OU8p12NKmXlqqIQcrVD2EWQWOiRwY99UovUWKJAky0EBT6hT7mtdxlNFlQk1d4NhylRDMGRX5kBi6NI3/AsQg2mg8CCI9wIRAe1VWwQVSgQLEn4qgghpMpfhOHJvQvLavw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jL/N+nAe; 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="jL/N+nAe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09D2F1F000FF; Thu, 17 Sep 2026 16:33:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789662820; bh=rtYEyCC7VKqkqWelOuwt2okny02CJhbQpnc+ekNFEso=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=jL/N+nAedFIcy7gClq40Pni5TcpDiYU3W6lU6py709+elTP01tPRn59duEgHxLXX0 kgCAUZfQP8LDRJaXC0n/N71unVUr4ytyGLpgajOR1/c4YelJsh50RSEglvq6YMlAKH biv1yaVW5dePVs5g/Hv/jlVM0hOEtIb8Jag/bYYIcYGUqIDRRHHq0XdtEgAa+WCKje /aLWPXFVlrCjlliJACtNcUtFXB+xYLlGB8XPAz53hZJeOTI9CTWK/FHjTV9mVLJ8+S 0aZkLZiwRcEq1Xk/+ULQ+CCWEkFgHVPGycWzsZevF4lLL2VqFx1YNlnabo+3m6UhqH SZaK2+UVVwY+g== From: "Lorenzo Stoakes (ARM)" Date: Thu, 17 Sep 2026 17:22:30 +0100 Subject: [PATCH v3 21/40] mm/gup: error out early on !VMA_MAYREAD_BIT VMAs 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-v3-21-4583d8a23bca@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=1289; i=ljs@kernel.org; h=from:subject:message-id; bh=NwkWQQ7fmwzL5QGJDJ/xCgQWUhs8DQGRd4wM7Vj8ofA=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLLWCB96M+ncMv0Z517wyC/y7rrGInXUMERpxZ9un+9eS ca/pBtPd5SyMIhxMciKKbI8/yK+P0gkbF7nBX83mDmsTCBDGLg4BWAiG00Z/tclL5u+8ccfuY17 fiz013R5ciLNuW2/7fq51ryiNWtXXapn+O/gpmbwXolVdG+JNs8Gjq3zWM8cSOs76LXyVfXh8/y uF/gA X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 When populating a VMA range via the aptly named populate_vma_page_range() an unreadable VMA will always eventually fail with -EFAULT. That a VMA is accessible is always checked, however VMA_MAYREAD_BIT is not. All user mappings always have VMA_MAYREAD_BIT set, so this check only impacts kernel mappings. It is implemented specifically to disallow population of uprobes XOL mappings which are exec-only. A nasty interaction with these mappings may occur if they are mlocked, so actively disallow this early. This allows a subsequent commit to remove the VM_IO check in __mm_populate() which otherwise requires non-MMIO mappings to be wrongly flagged simply as a workaround. Signed-off-by: Lorenzo Stoakes (ARM) --- mm/gup.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index c2dfcb4744bc..e6310a7cc05b 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1836,6 +1836,10 @@ long populate_vma_page_range(struct vm_area_struct *vma, if (!vma_is_accessible(vma)) return -EFAULT; + /* Unreadable VMAs also cannot be faulted in. */ + if (!vma_test(vma, VMA_MAYREAD_BIT)) + return -EFAULT; + gup_flags = FOLL_TOUCH; /* * We want to touch writable mappings with a write fault in order -- 2.55.0