From nobody Tue Jun 30 10:57:30 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A014C433F5 for ; Tue, 18 Jan 2022 23:52:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350305AbiARXwx (ORCPT ); Tue, 18 Jan 2022 18:52:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233354AbiARXww (ORCPT ); Tue, 18 Jan 2022 18:52:52 -0500 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C3C2C061574 for ; Tue, 18 Jan 2022 15:52:52 -0800 (PST) Received: by mail-pj1-x1033.google.com with SMTP id l16so799446pjl.4 for ; Tue, 18 Jan 2022 15:52:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=4/RjK8BN3JSAYkOl/QC9o65LtcnAhU3UXdD1BgVr6Dc=; b=I3JK5GxKJNosEutNRJEjnFEOYFwZ1QUsNrU8p+R6GhPQVxZou96OUTOJJJNUYvUXlI djYqsWuuEpIwlotwaIt6WThuRViY62QjMtOAC3oESQLeE07JPBa7iENB1R8NVtCdVozp KPhBoyoOoL+vLpnNDQRI2pTsZRefcPiWZD+vMtgXegOqwK8dmBlhC1pKrzn2n33WalQ6 u8I5lEIHn3e2WkVkySHo1yLDA/aqfeiJdTWy/oT2R7IK5/7BoD4gUBn88IlHzHMIwl5L tFptvPjevkIe/BK90fAKEO/eaOhkO2+zfCLCyHh4/USxnftehM/1SGXMrANgce6HlDQx gWXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=4/RjK8BN3JSAYkOl/QC9o65LtcnAhU3UXdD1BgVr6Dc=; b=XU4itxMmpEYHHlBB6hTt1PN30WsDz1FkIwIAjrY/uUesJRCIuhtrH9Kv5yBPIB7CEL qiKGSHENo+NJ+mf22ifKgh2Cm+C88PwrTmd2QB1LhSqjzZWUL0pXuibdLBO83uGabTne URdLfCHBmUnuk1dlJ7niUVnqD3sdMjGSLA66vha9Azr5EsY5iov3/WDfLyHkaHCqIo5n OIX/ahy386/UpKDb7ogLLnynOKevk5PHnZpVp8zUZqMIOmPtocIvkqdQNFBtkmDOPgUe bkrCBkIl9YFv+TTG8BpscSB2OboyYOWqmPugHsNV+150xOsrfj9+sw94ddWFzYQjSF/6 2HrQ== X-Gm-Message-State: AOAM533AhZmdL29BWAQ7+4x1DyOx7E5X++gnv24pFW2cXKWW09k0L1Qd hdRuiDHzMZYswFjThb3CzUs= X-Google-Smtp-Source: ABdhPJxiD2bVrhbvfdZNgIib+nJd6p1sFBUR9Rc3MGJm0eXE85gtCHvnl1zU6KKl3ctqvAbPK7LMAA== X-Received: by 2002:a17:903:32c4:b0:14a:67ae:3e03 with SMTP id i4-20020a17090332c400b0014a67ae3e03mr29666243plr.111.1642549971771; Tue, 18 Jan 2022 15:52:51 -0800 (PST) Received: from localhost (searspoint.nvidia.com. [216.228.112.21]) by smtp.gmail.com with ESMTPSA id h4sm18962329pfi.79.2022.01.18.15.52.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Jan 2022 15:52:51 -0800 (PST) From: Yury Norov To: Catalin Marinas , Will Deacon , Andrew Morton , Nicholas Piggin , Ding Tianhong , Anshuman Khandual , Matthew Wilcox , Alexey Klimov , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Yury Norov Subject: [PATCH] vmap(): don't allow invalid pages Date: Tue, 18 Jan 2022 15:52:44 -0800 Message-Id: <20220118235244.540103-1-yury.norov@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" vmap() takes struct page *pages as one of arguments, and user may provide an invalid pointer which would lead to DABT at address translation later. Currently, kernel checks the pages against NULL. In my case, however, the address was not NULL, and was big enough so that the hardware generated Address Size Abort on arm64. Interestingly, this abort happens even if copy_from_kernel_nofault() is used, which is quite inconvenient for debugging purposes.=20 This patch adds a pfn_valid() check into vmap() path, so that invalid mapping will not be created. RFC: https://lkml.org/lkml/2022/1/18/815 v1: use pfn_valid() instead of adding an arch-specific arch_vmap_page_valid(). Thanks to Matthew Wilcox for the hint. Signed-off-by: Yury Norov Suggested-by: Matthew Wilcox (Oracle) --- mm/vmalloc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d2a00ad4e1dd..a4134ee56b10 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -477,6 +477,8 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned lo= ng addr, return -EBUSY; if (WARN_ON(!page)) return -ENOMEM; + if (WARN_ON(!pfn_valid(page_to_pfn(page)))) + return -EINVAL; set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); (*nr)++; } while (pte++, addr +=3D PAGE_SIZE, addr !=3D end); --=20 2.30.2