From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 C0823C28CC0 for ; Wed, 29 May 2019 22:54:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88CB8242BC for ; Wed, 29 May 2019 22:54:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="i2m6pNEp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726498AbfE2Wyc (ORCPT ); Wed, 29 May 2019 18:54:32 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:39527 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726189AbfE2Wyc (ORCPT ); Wed, 29 May 2019 18:54:32 -0400 Received: by mail-pg1-f194.google.com with SMTP id 196so756053pgc.6 for ; Wed, 29 May 2019 15:54:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=jSKQLZwrhmnSigLvBb1y7bTu3QweUmRNvIXEtuAqha8=; b=i2m6pNEp//jAEdoVKlUepZrqCrxOeGMnhLpqIgwHYjCZuF1j3b+HZSW8SKuGwf1zDt 0bhyfZQPgyaivPOywVbLs91S4hzEVqMfYIG3C5qkLNxgmWMxMkjSo7UKUzLzHVsKOgvb 2r2aceu5kfodmmZkfuuAz0O4G4lZv5m/9XI0on/lp9xeE60SF9e+JH3tFD3v0ohkBZoV w+7veRU2N4ilJsskcWqJRw3UYj6ram4axcu3rhFFM6R8kQJtHkKuJlk17BYP4tYHHjY9 Ye2nbDpDWlhbhMpO7j+4cMkzYkUwtNMixcy88LTT3FUX0DPvQNzrI/nWRZXRQqSH6+ix kraA== 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; bh=jSKQLZwrhmnSigLvBb1y7bTu3QweUmRNvIXEtuAqha8=; b=FqKogu9YQtULHaa3x1zJVakdduC1zs1t+DaJ5Zl0TPiLpp9O94ZFFOxRIjRyRCuWfq n1XACy/wx5cTSpqA/Mu9LuAJrQBliCrvkZvV17RU4VgkWTRvZY1CPaycH8AalEOF7yik QODRLjeXXEBD+5cxRgBLnM4xi6oJiRnjj6LfbUqxrMWsidrgiPt/4mhs9KajwxtA5MvX rEOuUyVLW5JcU0MECpM2na2mXCfuvxHh2bO6KUV0cO6s0ofZDhrXUQE78PYGWideBMT/ wH8FeB+PUdzFkp2cQTOL/ZiYOLNcwf5Mhap5UoN2QfhaZU+MIEQqA5Un/Z52RWQYhPfw 1ZKQ== X-Gm-Message-State: APjAAAVNEbe58EcUVeJQFjI/m2t2GaTc4466z5McjgaBSO1M5rVPA2Q9 OR4bwGkartFKtuqzQI/AvA== X-Google-Smtp-Source: APXvYqwxpupc9N7njSo6f+msnHvsDLFKL5Sq7Tzn0RujPl74omIALXvHB2HQqQuQvOJWf8s9Yh/43Q== X-Received: by 2002:a63:d157:: with SMTP id c23mr504819pgj.125.1559170471934; Wed, 29 May 2019 15:54:31 -0700 (PDT) Received: from mylaptop.redhat.com ([2408:8207:782a:8650:1229:85cd:500a:f525]) by smtp.gmail.com with ESMTPSA id e12sm690266pfl.122.2019.05.29.15.54.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 May 2019 15:54:31 -0700 (PDT) From: Pingfan Liu To: linux-mm@kvack.org Cc: Pingfan Liu , Ira Weiny , Andrew Morton , Mike Rapoport , Dan Williams , Matthew Wilcox , John Hubbard , "Aneesh Kumar K.V" , Keith Busch , linux-kernel@vger.kernel.org Subject: [PATCH] mm/gup: fix omission of check on FOLL_LONGTERM in get_user_pages_fast() Date: Thu, 30 May 2019 06:54:04 +0800 Message-Id: <1559170444-3304-1-git-send-email-kernelfans@gmail.com> X-Mailer: git-send-email 2.7.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As for FOLL_LONGTERM, it is checked in the slow path __gup_longterm_unlocked(). But it is not checked in the fast path, which means a possible leak of CMA page to longterm pinned requirement through this crack. Place a check in the fast path. Signed-off-by: Pingfan Liu Cc: Ira Weiny Cc: Andrew Morton Cc: Mike Rapoport Cc: Dan Williams Cc: Matthew Wilcox Cc: John Hubbard Cc: "Aneesh Kumar K.V" Cc: Keith Busch Cc: linux-kernel@vger.kernel.org --- mm/gup.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index f173fcb..00feab3 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2235,6 +2235,18 @@ int get_user_pages_fast(unsigned long start, int nr_pages, local_irq_enable(); ret = nr; } +#if defined(CONFIG_CMA) + if (unlikely(gup_flags & FOLL_LONGTERM)) { + int i, j; + + for (i = 0; i < nr; i++) + if (is_migrate_cma_page(pages[i])) { + for (j = i; j < nr; j++) + put_page(pages[j]); + nr = i; + } + } +#endif if (nr < nr_pages) { /* Try to get the remaining pages with get_user_pages */ -- 2.7.5