From patchwork Fri Dec 30 15:43:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Yu X-Patchwork-Id: 37699 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:4e01:0:0:0:0:0 with SMTP id p1csp2949983wrt; Fri, 30 Dec 2022 07:46:38 -0800 (PST) X-Google-Smtp-Source: AMrXdXujReB/Nyw/n8kbq5h5O2dvCjPIIO8LhhqO9bLwSgJ+VbdLqSi+cJGP60w2GLekaXO5EMUg X-Received: by 2002:a05:6a20:6709:b0:af:aa38:12e0 with SMTP id q9-20020a056a20670900b000afaa3812e0mr34120916pzh.34.1672415198634; Fri, 30 Dec 2022 07:46:38 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1672415198; cv=none; d=google.com; s=arc-20160816; b=rDGI4PmNrqSVgmXZiEOKCm8YFlgDpfTSQnuOvx27/n4lqcjyB1nFr2r7hRiCiEP8xD y6Y8PpFkppWHfSLNJZRayziKSfmJIlv+X2iEuMhSmTbPfBrZJU5/eu2tJK9Srrn7lslA TPUMsyYVc83rdpJKYaEDl3hj0TYg/V06Vvla/bJ5dEp8zBqVImO95+2r1pjMmUqDA3ho PbFB/zWJqO4sV4XfIZqISSQsSiQfVImGVTlwTcrshTLuRY13fGoEKLVnQrlz8Ji+1rUB iahUM3dV2OmV0rNF3OwJuvMAYLbPwjHuVgWUIBSa+2TFjeTRQevySHLmhJ/DI42+qUYE KsTA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=5FkAXejz5uBbv0wStUEWSGXMribKnjxSOu1iG1c6Xyg=; b=VQmXdg9i8/xDV/vPewHJBhMqrdkQYzLn6xhK8EEORWkyg055sGXbbGkKi73k4ANKFF NUSBPtoun0bgnFPNDgku986WmYleJ0qXI0r9wRWeQVnnKXLfNo1XEUWE6ZyzrZhvzSBz QN/x2EvSfTO8td+ZU1dYSh48v+95pXafPNJqptUaBdFQKOvuaEi8cEJyVnlTICjEang5 8zVNKIrLxMhQYT/sz3tPyBtLrP+VZCgi5rFbpXdnE+xRkclLyiHMUULVAJG+RuDdCYla b6cOAm+rMwxD/9quOFZsQFUcPkHt8Z28IDcUDblrykpKGJK5zbZGg1tVhX5OMksWfgJU wlYw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=dphRm1gg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id 63-20020a630042000000b00476d7732344si22923885pga.741.2022.12.30.07.46.26; Fri, 30 Dec 2022 07:46:38 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=dphRm1gg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235274AbiL3Pns (ORCPT + 99 others); Fri, 30 Dec 2022 10:43:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235425AbiL3Pnm (ORCPT ); Fri, 30 Dec 2022 10:43:42 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA1B71B9F1 for ; Fri, 30 Dec 2022 07:43:41 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 968E5B81CC2 for ; Fri, 30 Dec 2022 15:43:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47014C433D2; Fri, 30 Dec 2022 15:43:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672415019; bh=MApoGiLoefSH4r+JR0/qNkucbn2OhIB8DVcH1zXvi+Y=; h=From:To:Cc:Subject:Date:From; b=dphRm1ggz5v5Qt0dr9xZHKVqpoJYqh+TqKT0mwChf9iJ0DXpweo8sWg6BglnJC6UG WWx/5ujniUx/QKMwjspaDHwCG3nd0P3RGZzNYG1W5vz8zI36ncnLPRIXcpUPtigKr/ CO43Bi/z41So2x/cU5Kd/dbcy3Rprh/oUzvEmmwxfY9VglK6Q6Swa75R/O28/gZs4L jASNVmrE4/tpLv4hsiV04XJZhqxK/FngemZnGvLgo9jReq34kcej0OftJ3/7WgxAE2 byqABOKT/GhBA3BmdFzQpk5JbY+07d9I+C1zd7fJ9Yo89i8KLCz1K0OJr72wXK9LpH yeUCiuANGj0xg== From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu Subject: [PATCH] f2fs: fix to avoid NULL pointer dereference in f2fs_issue_flush() Date: Fri, 30 Dec 2022 23:43:32 +0800 Message-Id: <20221230154332.5082-1-chao@kernel.org> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1753654438883521111?= X-GMAIL-MSGID: =?utf-8?q?1753654438883521111?= With below two cases, it will cause NULL pointer dereference when accessing SM_I(sbi)->fcc_info in f2fs_issue_flush(). a) If kthread_run() fails in f2fs_create_flush_cmd_control(), it will release SM_I(sbi)->fcc_info, - mount -o noflush_merge /dev/vda /mnt/f2fs - mount -o remount,flush_merge /dev/vda /mnt/f2fs -- kthread_run() fails - dd if=/dev/zero of=/mnt/f2fs/file bs=4k count=1 conv=fsync b) we will never allocate memory for SM_I(sbi)->fcc_info w/ below testcase, - mount -o ro /dev/vda /mnt/f2fs - mount -o rw,remount /dev/vda /mnt/f2fs - dd if=/dev/zero of=/mnt/f2fs/file bs=4k count=1 conv=fsync In order to fix this issue, let change as below: - fix error path handling in f2fs_create_flush_cmd_control(). - allocate SM_I(sbi)->fcc_info even if readonly is on. Signed-off-by: Chao Yu --- fs/f2fs/segment.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 2646575f43de..16f60c646cc2 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -663,8 +663,7 @@ int f2fs_create_flush_cmd_control(struct f2fs_sb_info *sbi) if (IS_ERR(fcc->f2fs_issue_flush)) { int err = PTR_ERR(fcc->f2fs_issue_flush); - kfree(fcc); - SM_I(sbi)->fcc_info = NULL; + fcc->f2fs_issue_flush = NULL; return err; } @@ -5137,11 +5136,9 @@ int f2fs_build_segment_manager(struct f2fs_sb_info *sbi) init_f2fs_rwsem(&sm_info->curseg_lock); - if (!f2fs_readonly(sbi->sb)) { - err = f2fs_create_flush_cmd_control(sbi); - if (err) - return err; - } + err = f2fs_create_flush_cmd_control(sbi); + if (err) + return err; err = create_discard_cmd_control(sbi); if (err)