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 36D10545296; Tue, 8 Sep 2026 20:11:58 +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=1788898320; cv=none; b=C78bBO+1GnBIgj/7vV8+nk7GWICtHxqgu43ae8i0WVM1nxKHyJJ8SvbdwGg6wy3vA1QgPsuyKzUEAwxskL46tmD3tXrJlXKkYcttXcriAZfPSM8xaA53zYQHGovqAgwR/Kh3xAHdLKqFkOjRLivz3TMQegJofwfKYJ8stgcfccs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788898320; c=relaxed/simple; bh=0xVbMIjlxJVEqff8evxHaJHGQIlqwm40RTiR4EqieKI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=D0pmEwWV7BmD4/LUDa5QhtQWVIIJQ4YxxHsjaJ2YlVjHxzIwfg4jDuZ+8DxQ7wm3ndeVuoSHjTIkDdWMYHH/l76r2FMZhDCEPV7NIJULeA/Zp/XAqBKbM8vAqlmH7oP036e3cvGq0zgtU7UH9ny8HNBRjA6Z06P/xK3H000UM9Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NX+FtPcF; 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="NX+FtPcF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C089D1F00A3D; Tue, 8 Sep 2026 20:11:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788898318; bh=W+GInhg3kWngclwIBI6LIN8QeZAUoh1n+q1azU6i5lM=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=NX+FtPcFw02/CuLs003CLYtuxHGTtCLAKxV0f7iniTsepgdSWBnGTIuct5GAXt/gR 4AjS3MIYwY7s0g7oTLUx1rlVaWjNrpenZbgmO+duwVRJQ3DLa0chfVyHoON7+r7+SU ihpWKH2iFPWgoAqwpA1Gel7jhEPnDre0zksv3fhbBpQ+onlKt4w4/7SvTCmg22qDMQ iznK6neaQBvBFhhlncbeDbNKkHF8Ko06C/767ZAi0wxnNw3TS9zVp/h2PDHglo8rYq faSKR/ddNCHv6kcMC8qH+2sYYtf5q0LoDmE8qkdz6lIGNl1tYNPgXkRonpfka4QDdY +PFM2WpG+OKIg== From: "Lorenzo Stoakes (ARM)" Date: Tue, 08 Sep 2026 21:01:24 +0100 Subject: [PATCH 20/39] mm/gup: error out early on !VMA_MAYREAD_BIT VMAs 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-v1-20-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=1289; i=ljs@kernel.org; h=from:subject:message-id; bh=0xVbMIjlxJVEqff8evxHaJHGQIlqwm40RTiR4EqieKI=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLIWZG5edsnojOAZATdxs5e7z35KcbDru7vC84n71n6bc pZZq1MedZSyMIhxMciKKbI8/yK+P0gkbF7nBX83mDmsTCBDGLg4BWAie8wYfrPGLqjSOKx2raUx YV8Xh1/HhgcGE+JF5S/IrD4jHylnFMzIsPbO5gK5rkTTD9dsElISF1zk95pTcNBN409F+e4TXHZ s7AA= 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 a4036c02e213..f5dc227bd6e1 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