From patchwork Tue Oct 27 13:52:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 312413 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 F3231C8300C for ; Tue, 27 Oct 2020 15:56:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B39F3206B2 for ; Tue, 27 Oct 2020 15:56:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603814197; bh=NnJvSZBQlr69j2vH0W5KuBx8RQ9qe/o/fabaoCgiro4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=y6fKxlLpOLrQAVwlXABaqmd4wG1MbYtEHkLRNtIU8g/gDqP3wuMNPC8WHd14vuL++ 5vTbZUWWpOm/oRkgL0rZIsa9SBkMbVXaPlnuw8lvywaF7UOaH3fOQp1ubUrgeX2l3j tRtwKk1FmMTwZXTPQ/qTxjzIodVh0xHZnpkg2ymM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1802640AbgJ0Pug (ORCPT ); Tue, 27 Oct 2020 11:50:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:32986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1801507AbgJ0Plb (ORCPT ); Tue, 27 Oct 2020 11:41:31 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8C07B222E9; Tue, 27 Oct 2020 15:41:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603813289; bh=NnJvSZBQlr69j2vH0W5KuBx8RQ9qe/o/fabaoCgiro4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=usrlSm355+WkuNsKVG1JMlBU1p74k31FNok4LzaQdou/BCEQnQkDOe0/a7UJQHHsx RcdP/K6PWc+B7nTKr5YpIbrkQY46I2meWeePM8vFnnzDJvwuZ9SQMNwNB+RyGyi86B LHiJMjhy6YqkQx9WRx41zpspADIqMnfgaxbpbjkc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jaegeuk Kim , Chao Yu , Jamie Iles , Chao Yu , Sasha Levin Subject: [PATCH 5.9 501/757] f2fs: wait for sysfs kobject removal before freeing f2fs_sb_info Date: Tue, 27 Oct 2020 14:52:31 +0100 Message-Id: <20201027135513.949074423@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135450.497324313@linuxfoundation.org> References: <20201027135450.497324313@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jamie Iles [ Upstream commit ae284d87abade58c8db7760c808f311ef1ce693c ] syzkaller found that with CONFIG_DEBUG_KOBJECT_RELEASE=y, unmounting an f2fs filesystem could result in the following splat: kobject: 'loop5' ((____ptrval____)): kobject_release, parent 0000000000000000 (delayed 250) kobject: 'f2fs_xattr_entry-7:5' ((____ptrval____)): kobject_release, parent 0000000000000000 (delayed 750) ------------[ cut here ]------------ ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x98 WARNING: CPU: 0 PID: 699 at lib/debugobjects.c:485 debug_print_object+0x180/0x240 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 699 Comm: syz-executor.5 Tainted: G S 5.9.0-rc8+ #101 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x4d8 show_stack+0x34/0x48 dump_stack+0x174/0x1f8 panic+0x360/0x7a0 __warn+0x244/0x2ec report_bug+0x240/0x398 bug_handler+0x50/0xc0 call_break_hook+0x160/0x1d8 brk_handler+0x30/0xc0 do_debug_exception+0x184/0x340 el1_dbg+0x48/0xb0 el1_sync_handler+0x170/0x1c8 el1_sync+0x80/0x100 debug_print_object+0x180/0x240 debug_check_no_obj_freed+0x200/0x430 slab_free_freelist_hook+0x190/0x210 kfree+0x13c/0x460 f2fs_put_super+0x624/0xa58 generic_shutdown_super+0x120/0x300 kill_block_super+0x94/0xf8 kill_f2fs_super+0x244/0x308 deactivate_locked_super+0x104/0x150 deactivate_super+0x118/0x148 cleanup_mnt+0x27c/0x3c0 __cleanup_mnt+0x28/0x38 task_work_run+0x10c/0x248 do_notify_resume+0x9d4/0x1188 work_pending+0x8/0x34c Like the error handling for f2fs_register_sysfs(), we need to wait for the kobject to be destroyed before returning to prevent a potential use-after-free. Fixes: bf9e697ecd42 ("f2fs: expose features to sysfs entry") Cc: Jaegeuk Kim Cc: Chao Yu Signed-off-by: Jamie Iles Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/sysfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 88ed9969cc862..5fe7d8fa93801 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -968,4 +968,5 @@ void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi) } kobject_del(&sbi->s_kobj); kobject_put(&sbi->s_kobj); + wait_for_completion(&sbi->s_kobj_unregister); }