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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69CD5C433F5 for ; Fri, 7 Oct 2022 19:57:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229751AbiJGT5h (ORCPT ); Fri, 7 Oct 2022 15:57:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbiJGT5g (ORCPT ); Fri, 7 Oct 2022 15:57:36 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC05BB40EF; Fri, 7 Oct 2022 12:57:35 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 8039B61747; Fri, 7 Oct 2022 19:57:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3AFFC433C1; Fri, 7 Oct 2022 19:57:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1665172654; bh=3ioUGXOwIHSSgzA9Xb+oDLQYye2pqliCmNaClnJCjcQ=; h=Date:To:From:Subject:From; b=P2zDwmoIqgaSbLiomwUGnP7CGTAJJMQqy8+FB/VEa22z2QglLDLjvrEzm2zjOAVfh 6ASQqIrk/Jin0gU3YaA4fDD9WPdKkHXhvCKXOPleHqcn+ypEX3mPGLYxZJo2ZzSyZZ BTYIFpVL/IaRWOzKLXEra21x70NlXJaPwMjEO+CU= Date: Fri, 07 Oct 2022 12:57:34 -0700 To: mm-commits@vger.kernel.org, stable@vger.kernel.org, konishi.ryusuke@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + nilfs2-fix-leak-of-nilfs_root-in-case-of-writer-thread-creation-failure.patch added to mm-hotfixes-unstable branch Message-Id: <20221007195734.D3AFFC433C1@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: nilfs2: fix leak of nilfs_root in case of writer thread creation failure has been added to the -mm mm-hotfixes-unstable branch. Its filename is nilfs2-fix-leak-of-nilfs_root-in-case-of-writer-thread-creation-failure.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-fix-leak-of-nilfs_root-in-case-of-writer-thread-creation-failure.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ryusuke Konishi Subject: nilfs2: fix leak of nilfs_root in case of writer thread creation failure Date: Fri, 7 Oct 2022 17:52:26 +0900 If nilfs_attach_log_writer() failed to create a log writer thread, it frees a data structure of the log writer without any cleanup. After commit e912a5b66837 ("nilfs2: use root object to get ifile"), this causes a leak of struct nilfs_root, which started to leak an ifile metadata inode and a kobject on that struct. In addition, if the kernel is booted with panic_on_warn, the above ifile metadata inode leak will cause the following panic when the nilfs2 kernel module is removed: kmem_cache_destroy nilfs2_inode_cache: Slab cache still has objects when called from nilfs_destroy_cachep+0x16/0x3a [nilfs2] WARNING: CPU: 8 PID: 1464 at mm/slab_common.c:494 kmem_cache_destroy+0x138/0x140 ... RIP: 0010:kmem_cache_destroy+0x138/0x140 Code: 00 20 00 00 e8 a9 55 d8 ff e9 76 ff ff ff 48 8b 53 60 48 c7 c6 20 70 65 86 48 c7 c7 d8 69 9c 86 48 8b 4c 24 28 e8 ef 71 c7 00 <0f> 0b e9 53 ff ff ff c3 48 81 ff ff 0f 00 00 77 03 31 c0 c3 53 48 ... Call Trace: ? nilfs_palloc_freev.cold.24+0x58/0x58 [nilfs2] nilfs_destroy_cachep+0x16/0x3a [nilfs2] exit_nilfs_fs+0xa/0x1b [nilfs2] __x64_sys_delete_module+0x1d9/0x3a0 ? __sanitizer_cov_trace_pc+0x1a/0x50 ? syscall_trace_enter.isra.19+0x119/0x190 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd ... Kernel panic - not syncing: panic_on_warn set ... This patch fixes these issues by calling nilfs_detach_log_writer() cleanup function if spawning the log writer thread fails. Link: https://lkml.kernel.org/r/20221007085226.57667-1-konishi.ryusuke@gmail.com Fixes: e912a5b66837 ("nilfs2: use root object to get ifile") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+7381dc4ad60658ca4c05@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/segment.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/fs/nilfs2/segment.c~nilfs2-fix-leak-of-nilfs_root-in-case-of-writer-thread-creation-failure +++ a/fs/nilfs2/segment.c @@ -2786,10 +2786,9 @@ int nilfs_attach_log_writer(struct super inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL); err = nilfs_segctor_start_thread(nilfs->ns_writer); - if (err) { - kfree(nilfs->ns_writer); - nilfs->ns_writer = NULL; - } + if (unlikely(err)) + nilfs_detach_log_writer(sb); + return err; } _ Patches currently in -mm which might be from konishi.ryusuke@gmail.com are nilfs2-fix-use-after-free-bug-of-struct-nilfs_root.patch nilfs2-fix-null-pointer-dereference-at-nilfs_bmap_lookup_at_level.patch nilfs2-fix-leak-of-nilfs_root-in-case-of-writer-thread-creation-failure.patch nilfs2-replace-warn_ons-by-nilfs_error-for-checkpoint-acquisition-failure.patch