From patchwork Tue Jan 26 04:44:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 12045195 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D366C43381 for ; Tue, 26 Jan 2021 04:45:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1A3A222B3B for ; Tue, 26 Jan 2021 04:45:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A3A222B3B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 93EA48D007C; Mon, 25 Jan 2021 23:45:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8EDE78D0076; Mon, 25 Jan 2021 23:45:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7B5528D007C; Mon, 25 Jan 2021 23:45:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0002.hostedemail.com [216.40.44.2]) by kanga.kvack.org (Postfix) with ESMTP id 62F658D0076 for ; Mon, 25 Jan 2021 23:45:35 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 275B43643 for ; Tue, 26 Jan 2021 04:45:35 +0000 (UTC) X-FDA: 77746687830.16.north05_350bec02758b Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id 050FC100E6903 for ; Tue, 26 Jan 2021 04:45:34 +0000 (UTC) X-HE-Tag: north05_350bec02758b X-Filterd-Recvd-Size: 6742 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Tue, 26 Jan 2021 04:45:34 +0000 (UTC) Received: by mail-pj1-f51.google.com with SMTP id gx1so1512230pjb.1 for ; Mon, 25 Jan 2021 20:45:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=99h/tGHmDH6XgvuK7c2jm1jDIuJ9R8UCtCFUngXSM7U=; b=IwKmqjfQbLTn1RKpBoK8CAF8l42LBNX53RdnmD5o9kWceKkSXKUiLW2Vc5W7+VoGLF E+Npet/lPXoDHvfDo0d5SUIX6RkTJcYckCFLVBsTqzYP6wtMbY4B/FgKeIyJ6AqC/9if vHN/JP1vjrwGG9UWr2vA/w7u/WeUwIUlGcWIJFv21fD1titV0hRjoQ2rwwh4qKx0UjXN qEsSrevguELE5CtDXlNJRa6HbZtMjYV4EalUglIC/ZeCpkDmEC5waRuIYiyehFLJR9cy l8jUEazE4JvWl9Olpj4yW3K2MLQp09VMmwSvclxrXiMu1W55B6ea28BcxtCP+Bo2qB6I Gf/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=99h/tGHmDH6XgvuK7c2jm1jDIuJ9R8UCtCFUngXSM7U=; b=M9AC5OisiN3REXNThDhbk+cVmbcj8vAz6hv4+HRAMLTJMks86QIPcCYsTQmzkvz8TE 1OXfTusrMOyXUkt1A7zJIFZtlq0M4xrjMsh7wwqVLb4qlzHA1//Xjer+xgJFjnZCVejv WhvvgGWKwwU6jMsIBnJBQSa22zFOuFhemaUOM06P1IY1HrujXbGc17Ea0v1Zb15hkwqE 8V/TQFrU2wE2156nzspNh5vIb22wTTSULLR6tRL9nYZxicBbDy6WIYYwHvnFHrMaySqO JkUwQWTqugI+a///MnkCt5Rkf6ORimgss3i5+Bzfd/hOAYUSYqvgXQ9SY8bysQCC8WKI /cig== X-Gm-Message-State: AOAM530YASZhF5gFe0HJBrldOPWfejgu29u58kRD9PRrmMKqUIV7mrbf tKuvZqQjzZ6CiqAUHjBWCLIh68fx8eA= X-Google-Smtp-Source: ABdhPJzY6nOUsbNiB/FKq11JNYzWxZB9lnLR1Og1caxfEXhmH2cWz6koWkbgJi1uiv9UYvm0mMKQtg== X-Received: by 2002:a17:902:b604:b029:df:fe41:f55d with SMTP id b4-20020a170902b604b02900dffe41f55dmr4145415pls.43.1611636333617; Mon, 25 Jan 2021 20:45:33 -0800 (PST) Received: from bobo.ozlabs.ibm.com (192.156.221.203.dial.dynamic.acc50-nort-cbr.comindico.com.au. [203.221.156.192]) by smtp.gmail.com with ESMTPSA id 68sm19272293pfg.90.2021.01.25.20.45.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Jan 2021 20:45:33 -0800 (PST) From: Nicholas Piggin To: linux-mm@kvack.org, Andrew Morton Cc: Nicholas Piggin , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Jonathan Cameron , Christoph Hellwig , Christophe Leroy , Rick Edgecombe , Ding Tianhong , Christoph Hellwig Subject: [PATCH v11 02/13] mm: apply_to_pte_range warn and fail if a large pte is encountered Date: Tue, 26 Jan 2021 14:44:59 +1000 Message-Id: <20210126044510.2491820-3-npiggin@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20210126044510.2491820-1-npiggin@gmail.com> References: <20210126044510.2491820-1-npiggin@gmail.com> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: apply_to_pte_range might mistake a large pte for bad, or treat it as a page table, resulting in a crash or corruption. Add a test to warn and return error if large entries are found. Reviewed-by: Christoph Hellwig Signed-off-by: Nicholas Piggin Reviewed-by: Miaohe Lin --- mm/memory.c | 66 +++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 49 insertions(+), 17 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index feff48e1465a..672e39a72788 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2440,13 +2440,21 @@ static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud, } do { next = pmd_addr_end(addr, end); - if (create || !pmd_none_or_clear_bad(pmd)) { - err = apply_to_pte_range(mm, pmd, addr, next, fn, data, - create, mask); - if (err) - break; + if (pmd_none(*pmd) && !create) + continue; + if (WARN_ON_ONCE(pmd_leaf(*pmd))) + return -EINVAL; + if (!pmd_none(*pmd) && WARN_ON_ONCE(pmd_bad(*pmd))) { + if (!create) + continue; + pmd_clear_bad(pmd); } + err = apply_to_pte_range(mm, pmd, addr, next, + fn, data, create, mask); + if (err) + break; } while (pmd++, addr = next, addr != end); + return err; } @@ -2468,13 +2476,21 @@ static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d, } do { next = pud_addr_end(addr, end); - if (create || !pud_none_or_clear_bad(pud)) { - err = apply_to_pmd_range(mm, pud, addr, next, fn, data, - create, mask); - if (err) - break; + if (pud_none(*pud) && !create) + continue; + if (WARN_ON_ONCE(pud_leaf(*pud))) + return -EINVAL; + if (!pud_none(*pud) && WARN_ON_ONCE(pud_bad(*pud))) { + if (!create) + continue; + pud_clear_bad(pud); } + err = apply_to_pmd_range(mm, pud, addr, next, + fn, data, create, mask); + if (err) + break; } while (pud++, addr = next, addr != end); + return err; } @@ -2496,13 +2512,21 @@ static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd, } do { next = p4d_addr_end(addr, end); - if (create || !p4d_none_or_clear_bad(p4d)) { - err = apply_to_pud_range(mm, p4d, addr, next, fn, data, - create, mask); - if (err) - break; + if (p4d_none(*p4d) && !create) + continue; + if (WARN_ON_ONCE(p4d_leaf(*p4d))) + return -EINVAL; + if (!p4d_none(*p4d) && WARN_ON_ONCE(p4d_bad(*p4d))) { + if (!create) + continue; + p4d_clear_bad(p4d); } + err = apply_to_pud_range(mm, p4d, addr, next, + fn, data, create, mask); + if (err) + break; } while (p4d++, addr = next, addr != end); + return err; } @@ -2522,9 +2546,17 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, pgd = pgd_offset(mm, addr); do { next = pgd_addr_end(addr, end); - if (!create && pgd_none_or_clear_bad(pgd)) + if (pgd_none(*pgd) && !create) continue; - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create, &mask); + if (WARN_ON_ONCE(pgd_leaf(*pgd))) + return -EINVAL; + if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) { + if (!create) + continue; + pgd_clear_bad(pgd); + } + err = apply_to_p4d_range(mm, pgd, addr, next, + fn, data, create, &mask); if (err) break; } while (pgd++, addr = next, addr != end);