From patchwork Tue May 23 19:03:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sungwoo Kim X-Patchwork-Id: 685397 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 F361DC7EE23 for ; Tue, 23 May 2023 19:04:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238195AbjEWTEP (ORCPT ); Tue, 23 May 2023 15:04:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233536AbjEWTEO (ORCPT ); Tue, 23 May 2023 15:04:14 -0400 Received: from mail-yb1-f181.google.com (mail-yb1-f181.google.com [209.85.219.181]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A72791; Tue, 23 May 2023 12:04:11 -0700 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ACHHUZ7q4JW7+x8k8wobTkNcopVEP1XKn8W2OeuB9TqTyMXF1cqswqQ6280FVBRRuKDNccBJcJmtng== X-Received: by 2002:a25:4d8:0:b0:bac:7294:4fb6 with SMTP id 207-20020a2504d8000000b00bac72944fb6mr2254036ybe.30.1684868650601; Tue, 23 May 2023 12:04:10 -0700 (PDT) Received: from tofu.cs.purdue.edu ([128.210.0.165]) by smtp.gmail.com with ESMTPSA id x3-20020a2584c3000000b00ba88763e5b5sm2226962ybm.2.2023.05.23.12.04.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 May 2023 12:04:10 -0700 (PDT) From: Sungwoo Kim Cc: wuruoyu@me.com, benquike@gmail.com, daveti@purdue.edu, Sungwoo Kim , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] Bluetooth: L2CAP: Fix use-after-free in bt_accept_unlink Date: Tue, 23 May 2023 15:03:48 -0400 Message-Id: <20230523190347.2584368-1-iam@sung-woo.kim> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org ================================================================== BUG: KASAN: use-after-free in bt_accept_unlink+0x77/0x1f0 net/bluetooth/af_bluetooth.c:189 Write of size 8 at addr ffff888104d59300 by task kworker/0:3/128 CPU: 0 PID: 128 Comm: kworker/0:3 Not tainted 6.2.0-00001-gef397bd4d5fb-dirty #58 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x72/0x95 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x175/0x478 mm/kasan/report.c:417 kasan_report+0xb1/0x130 mm/kasan/report.c:517 __list_del include/linux/list.h:114 [inline] __list_del_entry include/linux/list.h:137 [inline] list_del_init include/linux/list.h:206 [inline] bt_accept_unlink+0x77/0x1f0 net/bluetooth/af_bluetooth.c:189 l2cap_sock_teardown_cb+0x1c6/0x4c0 net/bluetooth/l2cap_sock.c:1586 l2cap_chan_del+0x108/0x5e0 net/bluetooth/l2cap_core.c:651 l2cap_chan_close+0x159/0x830 net/bluetooth/l2cap_core.c:859 l2cap_chan_timeout+0x14f/0x240 net/bluetooth/l2cap_core.c:452 process_one_work+0x4ea/0x8e0 kernel/workqueue.c:2289 worker_thread+0x364/0x8e0 kernel/workqueue.c:2436 kthread+0x1b9/0x200 kernel/kthread.c:376 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 Allocated by task 285: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x82/0x90 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:968 [inline] __kmalloc+0x5a/0x140 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] sk_prot_alloc+0x113/0x1f0 net/core/sock.c:2040 sk_alloc+0x36/0x3c0 net/core/sock.c:2093 l2cap_sock_alloc.constprop.0+0x39/0x1c0 net/bluetooth/l2cap_sock.c:1851 l2cap_sock_create+0x10d/0x220 net/bluetooth/l2cap_sock.c:1897 bt_sock_create+0x183/0x290 net/bluetooth/af_bluetooth.c:132 __sock_create+0x226/0x380 net/socket.c:1518 sock_create net/socket.c:1569 [inline] __sys_socket_create net/socket.c:1606 [inline] __sys_socket_create net/socket.c:1591 [inline] __sys_socket+0x112/0x200 net/socket.c:1639 __do_sys_socket net/socket.c:1652 [inline] __se_sys_socket net/socket.c:1650 [inline] __x64_sys_socket+0x40/0x50 net/socket.c:1650 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc Freed by task 285: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:523 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free mm/kasan/common.c:200 [inline] __kasan_slab_free+0x10a/0x190 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook mm/slub.c:1807 [inline] slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0x88/0x1f0 mm/slub.c:3800 sk_prot_free net/core/sock.c:2076 [inline] __sk_destruct+0x347/0x430 net/core/sock.c:2168 sk_destruct+0x9c/0xb0 net/core/sock.c:2183 __sk_free+0x82/0x220 net/core/sock.c:2194 sk_free+0x7c/0xa0 net/core/sock.c:2205 sock_put include/net/sock.h:1991 [inline] l2cap_sock_kill+0x256/0x2b0 net/bluetooth/l2cap_sock.c:1257 l2cap_sock_release+0x169/0x1c0 net/bluetooth/l2cap_sock.c:1427 __sock_release+0x80/0x150 net/socket.c:650 sock_close+0x19/0x30 net/socket.c:1368 __fput+0x17a/0x5c0 fs/file_table.c:320 task_work_run+0x132/0x1c0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x113/0x120 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x21/0x50 kernel/entry/common.c:296 do_syscall_64+0x4c/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x72/0xdc Last potentially related work creation: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0x97/0xb0 mm/kasan/generic.c:493 insert_work+0x33/0x180 kernel/workqueue.c:1358 __queue_work+0x410/0x960 kernel/workqueue.c:1517 rcu_work_rcufn+0x2e/0x40 kernel/workqueue.c:1754 rcu_do_batch kernel/rcu/tree.c:2246 [inline] rcu_core+0x43b/0xe70 kernel/rcu/tree.c:2506 __do_softirq+0x124/0x3f9 kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x22/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0x97/0xb0 mm/kasan/generic.c:493 __call_rcu_common.constprop.0+0x41/0x550 kernel/rcu/tree.c:2755 call_rcu_hurry include/linux/rcupdate.h:116 [inline] queue_rcu_work+0x79/0x90 kernel/workqueue.c:1774 process_one_work+0x4ea/0x8e0 kernel/workqueue.c:2289 worker_thread+0x364/0x8e0 kernel/workqueue.c:2436 kthread+0x1b9/0x200 kernel/kthread.c:376 ret_from_fork+0x2c/0x50 arch/x86/entry/entry_64.S:308 The buggy address belongs to the object at ffff888104d59000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 768 bytes inside of 1024-byte region [ffff888104d59000, ffff888104d59400) The buggy address belongs to the physical page: page:0000000067fcb39f refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104d58 head:0000000067fcb39f order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 anon flags: 0x200000000010200(slab|head|node=0|zone=2) raw: 0200000000010200 ffff888100041dc0 ffffea00041fa600 dead000000000003 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888104d59200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888104d59280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888104d59300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888104d59380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888104d59400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== l2cap_chan_timeout() tries to write on (struck sock*)chan->data that points to already free'd address by l2cap_sock_release(). This patch prevents this by clearing the timers in l2cap_sock_release() as l2cap_sock_cleanup_listen() does. Ack: This bug is found by FuzzBT with a modified Syzkaller. Other contributors are Ruoyu Wu and Hui Peng. Fixes: 1bff51ea59a9 (Bluetooth: fix use-after-free error in lock_sock_nested()) Signed-off-by: Sungwoo Kim --- net/bluetooth/l2cap_sock.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index eebe25610..cb274ee1c 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1423,6 +1423,7 @@ static int l2cap_sock_release(struct socket *sock) l2cap_chan_hold(chan); l2cap_chan_lock(chan); + __clear_chan_timer(chan); sock_orphan(sk); l2cap_sock_kill(sk);