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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,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 96091C282CE for ; Tue, 4 Jun 2019 23:33:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69F63206C1 for ; Tue, 4 Jun 2019 23:33:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559691193; bh=2VShnnzsVoYMc4XZkwnYUCfaeAm3shYu+Ux85v3avB0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k2Jm2xTfs7+y5Sfqm/fw1umr6oEsKW+3CvLS3c1gudgTfniaFUafTxiSqchTTbgL+ OQvthVuGhjvye15F70Ew9wt6tUMC2fCRtsgZlNPK2Q3V5U9qofP3MTMhFOo8hL1dYa R+orpC9XXJVxGtNpDzHsLtsIqRJ+r89kj5s4UO0k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726797AbfFDXdK (ORCPT ); Tue, 4 Jun 2019 19:33:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:60716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726736AbfFDXW3 (ORCPT ); Tue, 4 Jun 2019 19:22:29 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 123A0206C1; Tue, 4 Jun 2019 23:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559690548; bh=2VShnnzsVoYMc4XZkwnYUCfaeAm3shYu+Ux85v3avB0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mtg2SzEK4DzYUDO6+zqkfnRuZvb2nNId7Zzggy6C2PPcuLyVexts9fnLNrbkAFtsm d/Al0T0CkxeLNaANYp7cM/yDDga2rM496aLzlDwSWtwcvTq1shqOj2oMAzOqyyOA7r A3GnEWWEVVdzFBZL1AdcSUXg+2emMQ44Bj01EO8E= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: YueHaibing , Hulk Robot , Christoph Hellwig , Sasha Levin Subject: [PATCH AUTOSEL 5.1 08/60] configfs: fix possible use-after-free in configfs_register_group Date: Tue, 4 Jun 2019 19:21:18 -0400 Message-Id: <20190604232212.6753-8-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190604232212.6753-1-sashal@kernel.org> References: <20190604232212.6753-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: YueHaibing [ Upstream commit 35399f87e271f7cf3048eab00a421a6519ac8441 ] In configfs_register_group(), if create_default_group() failed, we forget to unlink the group. It will left a invalid item in the parent list, which may trigger the use-after-free issue seen below: BUG: KASAN: use-after-free in __list_add_valid+0xd4/0xe0 lib/list_debug.c:26 Read of size 8 at addr ffff8881ef61ae20 by task syz-executor.0/5996 CPU: 1 PID: 5996 Comm: syz-executor.0 Tainted: G C 5.0.0+ #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xa9/0x10e lib/dump_stack.c:113 print_address_description+0x65/0x270 mm/kasan/report.c:187 kasan_report+0x149/0x18d mm/kasan/report.c:317 __list_add_valid+0xd4/0xe0 lib/list_debug.c:26 __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] link_obj+0xb0/0x190 fs/configfs/dir.c:759 link_group+0x1c/0x130 fs/configfs/dir.c:784 configfs_register_group+0x56/0x1e0 fs/configfs/dir.c:1751 configfs_register_default_group+0x72/0xc0 fs/configfs/dir.c:1834 ? 0xffffffffc1be0000 iio_sw_trigger_init+0x23/0x1000 [industrialio_sw_trigger] do_one_initcall+0xbc/0x47d init/main.c:887 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x462e99 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f494ecbcc58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003 RBP: 00007f494ecbcc70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f494ecbd6bc R13: 00000000004bcefa R14: 00000000006f6fb0 R15: 0000000000000004 Allocated by task 5987: set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:497 kmalloc include/linux/slab.h:545 [inline] kzalloc include/linux/slab.h:740 [inline] configfs_register_default_group+0x4c/0xc0 fs/configfs/dir.c:1829 0xffffffffc1bd0023 do_one_initcall+0xbc/0x47d init/main.c:887 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 5987: set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:459 slab_free_hook mm/slub.c:1429 [inline] slab_free_freelist_hook mm/slub.c:1456 [inline] slab_free mm/slub.c:3003 [inline] kfree+0xe1/0x270 mm/slub.c:3955 configfs_register_default_group+0x9a/0xc0 fs/configfs/dir.c:1836 0xffffffffc1bd0023 do_one_initcall+0xbc/0x47d init/main.c:887 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881ef61ae00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 32 bytes inside of 192-byte region [ffff8881ef61ae00, ffff8881ef61aec0) The buggy address belongs to the page: page:ffffea0007bd8680 count:1 mapcount:0 mapping:ffff8881f6c03000 index:0xffff8881ef61a700 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0007ca4740 0000000500000005 ffff8881f6c03000 raw: ffff8881ef61a700 000000008010000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ef61ad00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ef61ad80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff8881ef61ae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ef61ae80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881ef61af00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 5cf6a51e6062 ("configfs: allow dynamic group creation") Reported-by: Hulk Robot Signed-off-by: YueHaibing Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- fs/configfs/dir.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 39843fa7e11b..920d350df37b 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1755,12 +1755,19 @@ int configfs_register_group(struct config_group *parent_group, inode_lock_nested(d_inode(parent), I_MUTEX_PARENT); ret = create_default_group(parent_group, group); - if (!ret) { - spin_lock(&configfs_dirent_lock); - configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata); - spin_unlock(&configfs_dirent_lock); - } + if (ret) + goto err_out; + + spin_lock(&configfs_dirent_lock); + configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata); + spin_unlock(&configfs_dirent_lock); + inode_unlock(d_inode(parent)); + return 0; +err_out: inode_unlock(d_inode(parent)); + mutex_lock(&subsys->su_mutex); + unlink_group(group); + mutex_unlock(&subsys->su_mutex); return ret; } EXPORT_SYMBOL(configfs_register_group); -- 2.20.1