From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B31F7606A31B for ; Mon, 26 Oct 2026 23:24:53 +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=apiQEG5i Received: by kanga.kvack.org (Postfix) id 45D016B05D6; Mon, 26 Oct 2026 19:24:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 42E236B05D7; Mon, 26 Oct 2026 19:24:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 343936B05D8; Mon, 26 Oct 2026 19:24:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 008906B05D6 for ; Mon, 26 Oct 2026 19:24:51 -0400 (EDT) Received: from smtpin07.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 899DDA857B for ; Mon, 26 Oct 2026 23:24:51 +0000 (UTC) X-FDA: 85366359582.07.0BAD7F8 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id D76121C0004 for ; Mon, 26 Oct 2026 23:24:49 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=apiQEG5i; spf=pass (imf21.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793057089; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=qQBYoODQ+YQypvvJ/bxf+QZV6zHatXlRhHg5nFuEkjY=; b=t30NfbQ7c9q9g627RR2/kP9AyKufyy116G0c/mRrtS8zC4y3KqQERfmf5QpznszDS2wQbL GNJJ6eGGugTddZSyLGgQLeuhI7KZaBSU4mY5ph/VNmbeqEBEc0coNCqIG3XXxmIGM+919d JbdcANVtBgdvxkaqc8o2d5U9bl4iv5g= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793057089; b=0FwfUjVAi6W91wRFnd60o60pa+5K07Lib7NGi9rfXZyzJvmBv/37YjaJ53kjWgST7nSjoM OqCbTlclbW2dZBV7bIeVx6Lho3+jYsw0xoTkZ1dGO7lUR/QV4iebNV17LdHqU+8j0j/bbX y1G8lz9rcCS5mrT1zkFYuu1P3ge/jGA= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=apiQEG5i; spf=pass (imf21.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 80986601F9; Mon, 26 Oct 2026 23:24:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E13A81F01828; Mon, 26 Oct 2026 23:24:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793057089; bh=qQBYoODQ+YQypvvJ/bxf+QZV6zHatXlRhHg5nFuEkjY=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=apiQEG5ikFEGzk70lvNqgcSuFbxsqv3KoY+cdbi/CXgRNvwDaThsY9M5RovpEEfFo JFu4/56U0E++OV3FBySS+H1tdOulH/Xt6CCEu3CGKpMEe0mUXtqJSJP9tRS6x5AJ31 m+ndyvHcLpq9OAW6nIACsnOC6HrvGmJMoMlpGQYK/jThBCwuCcSKNUEAxCW5t7xDNB fMVR4TiZ2J0xQ9Jvws7WPcLF4R7Nvdr7TVW1if1FFkP9Mbip4u6YJm2tr3KsE9sF6z xzpiQJB5NBcKKSuheBGTIIOW8lkxwrcHd257sDU9t8MbpXu6q2KjpsZ0YlL42ux0QL GAcroa840G2Qg== From: "David Hildenbrand (Arm)" Date: Tue, 27 Oct 2026 00:17:42 +0100 Subject: [PATCH 22/46] mm/gup: check for overflow when converting nr_pages to bytes in GUP-fast X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261027-fixes_core-v1-22-6f74bec9a5bb@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, stable@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1166; i=david@kernel.org; h=from:subject:message-id; bh=xmWshrb3+Xou48CaDcjPkXm82MkuoZo6NmHK5/nuQPc=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLLu35+aeTNfcdI97pS5wQm7FPTWmh1Unr01g9eJPX+Bl UAIt9SGjlIWBjEOBlkxRZag4PsGL1+uq61242OGmcPKBDKEgYtTACbCtYDhn2Fw+YTli4MZd/M1 hdXvvvO+YDZr6cVrBREH3i/9tpjT9AfD/1Q724PTdmWLiq3IYFMDOiS8cHKfUes+/QXfD+c+fba OCQA= X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: D76121C0004 X-Stat-Signature: ughus1gi5pxxc7up4hd8m5pxgs33ny9z X-Rspam-User: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-HE-Tag: 1793057089-681345 X-HE-Meta: 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 pQjTBaGM eQ/H7W5vQ2ae99AubuBkVs24+aqYOslESciqEJs/duWzwIhhlP5YQhtXNjvebSL+Ek1weJiMme3JSTXTDE60wO6bMLpQDKRjyE0BJnKNbvxyHIwKNOk/wkSi7ZrCOijDIhXiS80QBgV//5tehMh+Kdfvg7LmAog1Ea2dafD5j2v9FM/Kz8G80IWYo6jA3+QG/HS9AOhgXiiKMuprwLUAD/Rm0hiQuQMH0TR2rJgoDWxQaUc8EyqGdrc2najpDcEWZ9Jx0S9hiu4qQw/c5pMcN8GjoTy/WWAXDpmf2Ebtdwpdz97hWHWN0uCO5reOjtYbu3Vm86YBaWkpEYvxcVp6IfqeyA5CM39MWNp0IQW5KLStx7rQ= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 The overflow check in gup_fast_fallback() only covers the addition to start. The preceding nr_pages << PAGE_SHIFT can already have truncated the length on 32bit. Users such as RapidIO's rio_dma_transfer() can derive such page counts from a 64-bit userspace length. Let's just check_shl_overflow() to reject any such overflow with -EOVERFLOW early. Fixes: c28b1fc70390 ("mm/gup: reorganize internal_get_user_pages_fast()") Cc: stable@vger.kernel.org Signed-off-by: David Hildenbrand (Arm) --- mm/gup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 9906965893431..48e1bfe5ab9a9 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -3214,8 +3214,8 @@ static int gup_fast_fallback(unsigned long start, unsigned long nr_pages, might_lock_read(¤t->mm->mmap_lock); start = untagged_addr(start) & PAGE_MASK; - len = nr_pages << PAGE_SHIFT; - if (check_add_overflow(start, len, &end)) + if (check_shl_overflow(nr_pages, PAGE_SHIFT, &len) || + check_add_overflow(start, len, &end)) return -EOVERFLOW; if (end > TASK_SIZE_MAX) return -EFAULT; -- 2.43.0