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 A13C1606A31A for ; Thu, 29 Oct 2026 20:38:58 +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=YezDjZU2 Received: by kanga.kvack.org (Postfix) id C0C296B05D3; Thu, 29 Oct 2026 16:38:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BE3AC6B05D4; Thu, 29 Oct 2026 16:38:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AFA106B05D5; Thu, 29 Oct 2026 16:38:57 -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 8C4ED6B05D3 for ; Thu, 29 Oct 2026 16:38:57 -0400 (EDT) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 0DA69804B9 for ; Thu, 29 Oct 2026 20:38:57 +0000 (UTC) X-FDA: 85376827914.05.CFD2B1D Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf26.hostedemail.com (Postfix) with ESMTP id 348CD140006 for ; Thu, 29 Oct 2026 20:38:55 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=YezDjZU2; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf26.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793306335; 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=VnQ13mkoh6ozIDWGTVX+C6HT4vjQEoXrCm0MooEO04s=; b=iyjYXjrybIBiiiFbvIO8YCC0g94kgv0EuZVWc3ug/yTRB9G/UUGWvN6ibhwgiE2+btdy9g tv68b1ybMVNMMZh0ouV1dOLfkYjfVug/COk1kNgBkNyG+2vFmDRzAq9NmU7oTf+Kfjuzu4 x9fNCdOIzVqf4pfar44kMwEeC7O9HeU= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=YezDjZU2; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf26.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793306335; b=YidAIUEILUbgG1Md1Tz0GmMvY2bGynBSU+2hDA3gcUjgL8q6WwBg0+cmU9BVw7hzIBlXgV bTZHfqLm6OBoAtcIHYoXJzk1g7XqLGy1Zc1NwjbcH3kmOKnW0sj+bXbp9Wr3AsWhLS+bKK wrt6/9bR6+fVGoNABNQTDd4HvyCdOKo= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 7EE5F4366B; Thu, 29 Oct 2026 20:38:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 736391F01829; Thu, 29 Oct 2026 20:38:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793306334; bh=VnQ13mkoh6ozIDWGTVX+C6HT4vjQEoXrCm0MooEO04s=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=YezDjZU2yi5cWmUqfDHysvLO9HwSd76jRjz2DKKiJKmvX5TchaYVydd2c1v8z1JoG ukY6PBjO2jSZ2MQea3k0Ss09Ud/uCHu5P7yCWtRSy256Tb4AzyVTKkJiiDAcgduQg7 xrppl9xLjFoWu1REw195bMUI8zpRl7qt7xONHzxWgUiB25CSuIO+I9FXJAhMAXvIxe 9vFj0edvZ4NkCIz0Xn+Jfn8csY2hF2LHytvnUSwkq/J8TpxTtMH2yoRQoiT7o4M8eY 68bluiNVhI3XJ1TLn1f1fRogMry8mga7lzsNOhsJevsO9wM1nRRKTRUXOiJoCR3V2/ aAjnkIfXbMGHA== From: "David Hildenbrand (Arm)" Date: Thu, 29 Oct 2026 21:33:17 +0100 Subject: [PATCH v2 22/47] 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: <20261029-fixes_core-v2-22-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> In-Reply-To: <20261029-fixes_core-v2-0-a64ce7f83abb@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=1309; i=david@kernel.org; h=from:subject:message-id; bh=1C5sa/S2cZ8sLgA0w/Gi6tvhiudETPPmM19hS9JNC5Q=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLIer21vLdw0040r6ZRnZU1d3rZlDw/pO7lrXgmoYp4wY /tajl38HaUsDGIcDLJiiixBwfcNXr5cV1vtxscMM4eVCWQIAxenAEzEYTkjw+vlHL3B1hunvHr1 /9a717nmGp87rIONvDT4+Q4o6P65soKRofVY6M6Jcm9fbfnHGVBQEHrm94n22fOMc+78Cd67bJV 1FjcA X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 348CD140006 X-Stat-Signature: ih1bcsbsddesp816z4ya9buqoggxqczu X-Spam-Status: No, score=-18.8 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-Rspam-User: X-HE-Tag: 1793306335-743556 X-HE-Meta: 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 OuyPuMfk mHsEkVRtQqLOuI5kXqtuCon2mN8KKUkUJisFrHpp34dZu5t9J/I114TjXDw9YDVyQDMS+PKGtm3E4RcPPN0cDFt+zvGF2mHzOi//aFrWHmeE2JZlwGpNs9/CIFZPe+6JRYuA1Wb+v3e/TbBFDIQJyR+pz0jzX9UTlvdFYCNV8z33uSRbDJ7woojmhaeBZjB3qs9wX9acwCXpkGJ20amNvsDTsK5CoFQVpCUay8igXUmSRa2K99SzzbJ+9zIM06Bcw2bbCkAPgVDSQa8KgKz+XtOTWnkVNSpOClKUQEME/lH2FIQpBPPy2uVTemneHdLUY+vhFRHseOEOX0AaE3kPTLHoaCzL+1BXfbq3pmmfuxOXGwZDtBdW3IJTgsQ== 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 Reviewed-by: Lorenzo Stoakes (ARM) Acked-by: Muchun Song Reviewed-by: Barry Song 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 1c2ac7c66c30..ba4907b35232 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -3225,8 +3225,8 @@ 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