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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, 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 1B778C636CD for ; Thu, 15 Jul 2021 18:54:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0300C613E3 for ; Thu, 15 Jul 2021 18:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241386AbhGOS5D (ORCPT ); Thu, 15 Jul 2021 14:57:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:33468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241018AbhGOS4o (ORCPT ); Thu, 15 Jul 2021 14:56:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 396A8613D1; Thu, 15 Jul 2021 18:53:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626375230; bh=uTfMtEl8lNqdnF0HOgRYsgNEB8zxn1gq3kZz34x9N7c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gRrL9uAa1MaI7EVCkgC5nUHBZipo9AB77uNi5tITrHoBlGqOJbSpOAC0+h5DO9ybk 78X3R3+BB6H/UcMVcvQkEWAL+jXX/ovIRcNZQC26KHm0l+49EmhHSLuRcFi3wc0s9S CXzjm4jyolLZichM9Wj99d3Ib4qL6A6wB9KOijUo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+9d90dad32dd9727ed084@syzkaller.appspotmail.com, Chao Yu , Jaegeuk Kim Subject: [PATCH 5.10 215/215] f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances Date: Thu, 15 Jul 2021 20:39:47 +0200 Message-Id: <20210715182637.438443933@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182558.381078833@linuxfoundation.org> References: <20210715182558.381078833@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chao Yu commit cad83c968c2ebe97905f900326988ed37146c347 upstream. As syzbot reported, there is an use-after-free issue during f2fs recovery: Use-after-free write at 0xffff88823bc16040 (in kfence-#10): kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486 f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945 mount_bdev+0x26c/0x3a0 fs/super.c:1367 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1497 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is multi f2fs filesystem instances can race on accessing global fsync_entry_slab pointer, result in use-after-free issue of slab cache, fixes to init/destroy this slab cache only once during module init/destroy procedure to avoid this issue. Reported-by: syzbot+9d90dad32dd9727ed084@syzkaller.appspotmail.com Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/f2fs.h | 2 ++ fs/f2fs/recovery.c | 23 ++++++++++++++--------- fs/f2fs/super.c | 8 +++++++- 3 files changed, 23 insertions(+), 10 deletions(-) --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3462,6 +3462,8 @@ void f2fs_destroy_garbage_collection_cac */ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only); bool f2fs_space_for_roll_forward(struct f2fs_sb_info *sbi); +int __init f2fs_create_recovery_cache(void); +void f2fs_destroy_recovery_cache(void); /* * debug.c --- a/fs/f2fs/recovery.c +++ b/fs/f2fs/recovery.c @@ -777,13 +777,6 @@ int f2fs_recover_fsync_data(struct f2fs_ quota_enabled = f2fs_enable_quota_files(sbi, s_flags & SB_RDONLY); #endif - fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry", - sizeof(struct fsync_inode_entry)); - if (!fsync_entry_slab) { - err = -ENOMEM; - goto out; - } - INIT_LIST_HEAD(&inode_list); INIT_LIST_HEAD(&tmp_inode_list); INIT_LIST_HEAD(&dir_list); @@ -856,8 +849,6 @@ skip: } } - kmem_cache_destroy(fsync_entry_slab); -out: #ifdef CONFIG_QUOTA /* Turn quotas off */ if (quota_enabled) @@ -867,3 +858,17 @@ out: return ret ? ret: err; } + +int __init f2fs_create_recovery_cache(void) +{ + fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry", + sizeof(struct fsync_inode_entry)); + if (!fsync_entry_slab) + return -ENOMEM; + return 0; +} + +void f2fs_destroy_recovery_cache(void) +{ + kmem_cache_destroy(fsync_entry_slab); +} --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4027,9 +4027,12 @@ static int __init init_f2fs_fs(void) err = f2fs_create_checkpoint_caches(); if (err) goto free_segment_manager_caches; - err = f2fs_create_extent_cache(); + err = f2fs_create_recovery_cache(); if (err) goto free_checkpoint_caches; + err = f2fs_create_extent_cache(); + if (err) + goto free_recovery_cache; err = f2fs_create_garbage_collection_cache(); if (err) goto free_extent_cache; @@ -4078,6 +4081,8 @@ free_garbage_collection_cache: f2fs_destroy_garbage_collection_cache(); free_extent_cache: f2fs_destroy_extent_cache(); +free_recovery_cache: + f2fs_destroy_recovery_cache(); free_checkpoint_caches: f2fs_destroy_checkpoint_caches(); free_segment_manager_caches: @@ -4103,6 +4108,7 @@ static void __exit exit_f2fs_fs(void) f2fs_exit_sysfs(); f2fs_destroy_garbage_collection_cache(); f2fs_destroy_extent_cache(); + f2fs_destroy_recovery_cache(); f2fs_destroy_checkpoint_caches(); f2fs_destroy_segment_manager_caches(); f2fs_destroy_node_manager_caches();