From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793057540; b=au4U3uwP9/TN7uE+ila8qhYoXapqstmDj2AgYT6oAzjBAcEJjnAb2Qli3AmLQlfoL4Xe l8X6b7zxCRaWVB259eWBhRtpM1tHzPLfOD8g8HpV2MPFk7ARJNQUk4Yj6ADBAmX2MzGRE lLhmE7Ay8Ahpes07SbOq6yDZOjjZlxqlbyzydpFjF7Zeqt+4RKW1ohuHOaysk1uVesKH9 nAYDO+awYHV7tB6iKhE43aKmEDvOodBxDpi16/De5etQ31u9900xtHqxI4fEx0xurdzPd O4A0bESsIV/kYH1a/2HCLeb4xlaM/iLLXr+DBc/fBNUmIbQ3X9WMxXKm0oBgy0qod/A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793057540; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=leDMySoi7QnuGrXCT7kUTF7p3M2NeDPBgSV/0vbZ0BI=; b=4ZhZr27NY60rwCCJuH5JlxaLpssP4bm2HE9COTf99R8qSn9R4u9zyWngSvuNRjFJu8sH oCEAgjpmfaDew3yl6+EHMmH18xTHq9ZNsJrV2ZXzvqCxCek1p//8lnMx5RrKiURRWnskR InjYtkoyupu5+mylOV7dYMg8oKv5PYUkFRSCvOQ/xvrSmbDCN4bssAZ4pwqWJdRb5eoQa clI0YNs0aQ1+/W0g6mz2kydGS9KM79uJdLCvWxqhm5e09uW5fwVG/i4R/hLHP5o9NsZ99 1fD2CHv2M666d9LWSKqWix0PlLDZqoSIVRGxWOeg73k5q7WicpZ1/bEDUovb06OH76g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=L9akpim6; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54CAD606A31D; Mon, 26 Oct 2026 23:32:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=L9akpim6 Received: by smtp.kernel.org (Postfix) with ESMTPSA id C72011F01825; Mon, 26 Oct 2026 23:32:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793057540; bh=leDMySoi7QnuGrXCT7kUTF7p3M2NeDPBgSV/0vbZ0BI=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=L9akpim6QbyBegiqBFdq/baFvmFgEdwCFWOYawuBvlzKXZmVSx0OXUe0vIKVc29Kq qFDhmjhE2XC8r2UET7MbseG82Yrlr5rl8uhm+FWZXg9zSHHjcPx6jOzdtkZAUAd57/ SUaqIU3cTuXQ5rkuIOkuugP4Oddi+rqpi0RzyFZcXrXMvV1AJRJeL0Ka60cc/6lFzl 3aj7CVp9NxQgtlAVViDSO2yiUZAwQ3wkx24AZ9ntSDPW+IGf2vjdQTXbtW5e5vPduc PYBh4bWzA7jbOLzBvw10CaUrJ2jvgAzk/WB3Tm80LB/7B3bjWitIFuSzSjELUy2vBJ OVrw1PteZgGXQ== From: "David Hildenbrand (Arm)" Date: Tue, 27 Oct 2026 00:18:06 +0100 Subject: [PATCH 46/46] fs/proc/task_mmu: refuse addresses beyond 32 bits on 32bit X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261027-fixes_core-v1-46-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> In-Reply-To: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> To: Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1648; i=david@kernel.org; h=from:subject:message-id; bh=+RaX15JldLvyrOg9i/7002o3Wko+CCA0o+GE3n4B9o0=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLLu3595P/+VmdMlLqcHjo7hx5XfCereZwuyfqL6dWnoT tPbz1nLO0pZGMQ4GGTFFFmCgu8bvHy5rrbajY8ZZg4rE8gQBi5OAZjIuT2MDAtnL/pcH+sjlak6 xTFMq1Epryj302Srs5J1+1ufKrr0T2FkuFqsNvv532l6H9VM/3dH69amCF5+VDmd8zXP8lDXW2x ruQE= X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A From: Josef Bacik The addresses in struct pm_scan_arg are 64 bits wide. The first thing pagemap_scan_get_args() does with them is to cast them to unsigned long. On a 32-bit kernel the upper half is dropped without a word: PAGEMAP_SCAN of 0x100001000-0x100002000 scans, and with PM_SCAN_WP_MATCHING write-protects, 0x1000-0x2000, stores the result at the lower half of vec, and reports success. Return -EFAULT, as for other addresses outside of the address space. This is probably not worth CCing stable. Fix generated by an LLM and sent by Josef Bacik in private. Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs") Signed-off-by: Josef Bacik Acked-by: Lorenzo Stoakes (ARM) Signed-off-by: David Hildenbrand (Arm) --- fs/proc/task_mmu.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 7452b695fdaec..762b6dbb81e4a 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -3032,6 +3032,12 @@ static int pagemap_scan_get_args(struct pm_scan_arg *arg, arg->category_anyof_mask | arg->return_mask) & ~PM_SCAN_CATEGORIES) return -EINVAL; + /* Don't cut 64-bit numbers down to addresses that happen to work. */ + if (arg->start != (unsigned long)arg->start || + arg->end != (unsigned long)arg->end || + arg->vec != (unsigned long)arg->vec) + return -EFAULT; + arg->start = untagged_addr((unsigned long)arg->start); arg->end = untagged_addr((unsigned long)arg->end); arg->vec = untagged_addr((unsigned long)arg->vec); -- 2.43.0