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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 7FA34C433E0 for ; Tue, 5 Jan 2021 23:50:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5109C22D74 for ; Tue, 5 Jan 2021 23:50:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726894AbhAEXuS (ORCPT ); Tue, 5 Jan 2021 18:50:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726215AbhAEXuS (ORCPT ); Tue, 5 Jan 2021 18:50:18 -0500 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29777C061574 for ; Tue, 5 Jan 2021 15:49:38 -0800 (PST) Received: by mail-pl1-x62f.google.com with SMTP id 4so616635plk.5 for ; Tue, 05 Jan 2021 15:49:38 -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:mime-version :content-transfer-encoding; bh=whc2U5gu5zwKqW7Z1BCd12zYqBfLakFsyLK0IzuWzP8=; b=RSYt8aWDjjxG6udavDTUY19W7lHxifCi8492IhANNtipB66/pAWN4AWXhxP+tKJjzj NAt6EZe3Zc49FsV8iZqgXQYgJhiyWJGhH2M+FU4a+hrkDhxcKleEPmDxC/dbtEfz1xUt pCyc5Z1UjpWdgzYdXymMqBg4/iQss87JLDkc3GBlPcvhXS8glcjpf6uYvbc7H/RMDvu/ CFA768T2YFosp2nuzRHipHGrkO/FmljBtLCcy/EAk49H2eGvFNq+g4C5l8ia3GpKPluR YyRYxluQN/pzIVaPgOrg0Aeix4rrrI4HowMzphddpO2W6+g+v6qwwgOxUHV7jgOodkf9 oyDA== 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:mime-version :content-transfer-encoding; bh=whc2U5gu5zwKqW7Z1BCd12zYqBfLakFsyLK0IzuWzP8=; b=InyyujnaGFSWnXF9XMTIIbuAWv9wmXSbvxfpUx50+JsXyckbaOsNosdjcDbOGOEk4O VkMmuF8u3M3ZAJgK3GRrySKKNDJz1vlsDIkL3IKfMC887oCCpZHwxKtyduXdlzNMRhzy W6lT//hD7O8SU9ryKf10X0YNbKS8EjKOQHuzH/iMV6fMbDAY28HwCtKu1QvxDMWWfE07 w0xH2hOC1J23r5BNkq8plQjpW8/n987h81MLGJA72WWQeE2Ipt1b16b9rDgnTO0MBf41 Q9N61Dyua6UcX2kyRX6SRg4hL3KO0bpcylRiLRxfvQQOPBiPv6xobe6QS0ZyszhcmvG1 z41w== X-Gm-Message-State: AOAM530bgNln7mRCGne9wYXTe9ExzBaw/kswFHZV48ft8flWxkEmsCEm ZWeOL8zQM1LxIBLc7ileWSPzW/N/PAk= X-Google-Smtp-Source: ABdhPJwL704VReSw6jgByR6yvKwqCTroZ13+bPc6/tofWoYLUxpY5mR6MoNopmnlk4n6HDG6LBwFJA== X-Received: by 2002:a17:902:b693:b029:da:e92c:fc23 with SMTP id c19-20020a170902b693b02900dae92cfc23mr1531675pls.55.1609890577267; Tue, 05 Jan 2021 15:49:37 -0800 (PST) Received: from daehojeong1.seo.corp.google.com ([2401:fa00:d:11:a6ae:11ff:fe18:6ce2]) by smtp.gmail.com with ESMTPSA id 8sm285724pgx.48.2021.01.05.15.49.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Jan 2021 15:49:36 -0800 (PST) From: Daeho Jeong To: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com Cc: Daeho Jeong , Colin Ian King Subject: [PATCH v2] f2fs: fix null page reference in redirty_blocks Date: Wed, 6 Jan 2021 08:49:28 +0900 Message-Id: <20210105234928.1598326-1-daeho43@gmail.com> X-Mailer: git-send-email 2.29.2.729.g45daf8777d-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daeho Jeong By Colin's static analysis, we found out there is a null page reference under low memory situation in redirty_blocks. I've made the page finding loop stop immediately and return an error not to cause further memory pressure when we run into a failure to find a page under low memory condition. Signed-off-by: Daeho Jeong Reported-by: Colin Ian King Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE") --- v2: changed error value and quit the page finding loop immediately when error occurs --- fs/f2fs/file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 9e5275716be8..d27173c24391 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4060,8 +4060,10 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len) for (i = 0; i < page_len; i++, redirty_idx++) { page = find_lock_page(mapping, redirty_idx); - if (!page) - ret = -ENOENT; + if (!page) { + ret = -ENOMEM; + break; + } set_page_dirty(page); f2fs_put_page(page, 1); f2fs_put_page(page, 0); -- 2.29.2.729.g45daf8777d-goog