From patchwork Thu Jul 23 07:57:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhang, Qiang" X-Patchwork-Id: 11680405 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A51C313B1 for ; Thu, 23 Jul 2020 07:58:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 954A4206C1 for ; Thu, 23 Jul 2020 07:58:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727940AbgGWH60 (ORCPT ); Thu, 23 Jul 2020 03:58:26 -0400 Received: from mail1.windriver.com ([147.11.146.13]:35700 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726303AbgGWH60 (ORCPT ); Thu, 23 Jul 2020 03:58:26 -0400 Received: from ALA-HCB.corp.ad.wrs.com (ala-hcb.corp.ad.wrs.com [147.11.189.41]) by mail1.windriver.com (8.15.2/8.15.2) with ESMTPS id 06N7w41n029713 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Thu, 23 Jul 2020 00:58:04 -0700 (PDT) Received: from pek-qzhang2-d1.wrs.com (128.224.162.183) by ALA-HCB.corp.ad.wrs.com (147.11.189.41) with Microsoft SMTP Server id 14.3.487.0; Thu, 23 Jul 2020 00:57:51 -0700 From: To: , , CC: , Subject: [PATCH] ceph: KASAN: use-after-free Read in ceph_mdsc_destroy Date: Thu, 23 Jul 2020 15:57:49 +0800 Message-ID: <20200723075749.13043-1-qiang.zhang@windriver.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org From: Zhang Qiang When the mdsc ptr is free, we should assign "thefsc->mdsc" a null ptr, in ceph_mdsc_init func. CPU: 0 PID: 15653 Comm: syz-executor.3 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 timer_is_static_object+0x7a/0x90 kernel/time/timer.c:611 debug_object_assert_init lib/debugobjects.c:866 [inline] debug_object_assert_init+0x1df/0x2e0 lib/debugobjects.c:841 debug_timer_assert_init kernel/time/timer.c:728 [inline] debug_assert_init kernel/time/timer.c:773 [inline] del_timer+0x6d/0x110 kernel/time/timer.c:1196 try_to_grab_pending kernel/workqueue.c:1249 [inline] __cancel_work_timer+0x12d/0x700 kernel/workqueue.c:3092 ceph_mdsc_stop fs/ceph/mds_client.c:4660 [inline] ceph_mdsc_destroy+0x50/0x140 fs/ceph/mds_client.c:4679 destroy_fs_client+0x13/0x200 fs/ceph/super.c:720 ceph_get_tree+0x9e5/0x1660 fs/ceph/super.c:1110 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] do_mount+0x1592/0x1fe0 fs/namespace.c:3200 __do_sys_mount fs/namespace.c:3410 [inline] __se_sys_mount fs/namespace.c:3387 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1d9 Code: Bad RIP value. RSP: 002b:00007f33d2bc0c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000001f400 RCX: 000000000045c1d9 RDX: 0000000020000140 RSI: 00000000200000c0 RDI: 00000000200005c0 RBP: 000000000078bf50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007fffaad3cc8f R14: 00007f33d2bc19c0 R15: 000000000078bf0c Allocated by task 15653: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 kmem_cache_alloc_trace+0x14f/0x2d0 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] ceph_mdsc_init+0x47/0xf10 fs/ceph/mds_client.c:4351 ceph_get_tree+0x4fe/0x1660 fs/ceph/super.c:1063 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] do_mount+0x1592/0x1fe0 fs/namespace.c:3200 __do_sys_mount fs/namespace.c:3410 [inline] __se_sys_mount fs/namespace.c:3387 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 15653: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 ceph_mdsc_init+0xc64/0xf10 fs/ceph/mds_client.c:4422 ceph_get_tree+0x4fe/0x1660 fs/ceph/super.c:1063 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] do_mount+0x1592/0x1fe0 fs/namespace.c:3200 __do_sys_mount fs/namespace.c:3410 [inline] __se_sys_mount fs/namespace.c:3387 [inline] __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88809e482000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 896 bytes inside of 4096-byte region [ffff88809e482000, ffff88809e483000) The buggy address belongs to the page: page:ffffea0002792080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea0002792080 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002792008 ffffea000241dc08 ffff8880aa002000 raw: 0000000000000000 ffff88809e482000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809e482280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809e482300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809e482380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809e482400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809e482480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: f9009efac49c ("ceph: add dentry lease metric support") Reported-by: syzbot+b57f46d8d6ea51960b8c@syzkaller.appspotmail.com Signed-off-by: Zhang Qiang --- fs/ceph/mds_client.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index a50497142e59..6d819c285b05 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4420,6 +4420,7 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) kfree(mdsc->mdsmap); err_mdsc: kfree(mdsc); + fsc->mdsc = NULL; return err; }