audit: type=1804 audit(1598541143.093:69): pid=20644 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir394393479/syzkaller.h8UmDY/110/bus" dev="sda1" ino=16154 res=1 ====================================================== WARNING: possible circular locking dependency detected 4.14.195-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/15309 is trying to acquire lock: ("%s"hdev->name#2){+.+.}, at: [] start_flush_work kernel/workqueue.c:2860 [inline] ("%s"hdev->name#2){+.+.}, at: [] flush_work+0x387/0x770 kernel/workqueue.c:2892 but task is already holding lock: (&hdev->lock){+.+.}, at: [] hci_dev_do_close+0x210/0xc50 net/bluetooth/hci_core.c:1607 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&hdev->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 hci_cc_write_scan_enable net/bluetooth/hci_event.c:360 [inline] hci_cmd_complete_evt+0x4f1a/0x9590 net/bluetooth/hci_event.c:2839 hci_event_packet+0x1a5d/0x7d1d net/bluetooth/hci_event.c:5321 hci_rx_work+0x3e6/0x970 net/bluetooth/hci_core.c:4244 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #1 ((&hdev->rx_work)){+.+.}: process_one_work+0x736/0x14a0 kernel/workqueue.c:2092 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #0 ("%s"hdev->name#2){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 start_flush_work kernel/workqueue.c:2861 [inline] flush_work+0x3ac/0x770 kernel/workqueue.c:2892 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2964 hci_conn_del+0x43/0x620 net/bluetooth/hci_conn.c:575 hci_conn_hash_flush+0x189/0x220 net/bluetooth/hci_conn.c:1377 hci_dev_do_close+0x542/0xc50 net/bluetooth/hci_core.c:1620 hci_unregister_dev+0x170/0x7a0 net/bluetooth/hci_core.c:3191 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa08/0x27f0 kernel/exit.c:865 do_group_exit+0x100/0x2e0 kernel/exit.c:962 get_signal+0x38d/0x1ca0 kernel/signal.c:2423 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: "%s"hdev->name#2 --> (&hdev->rx_work) --> &hdev->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hdev->lock); lock((&hdev->rx_work)); lock(&hdev->lock); lock("%s"hdev->name#2); *** DEADLOCK *** 2 locks held by syz-executor.4/15309: #0: (&hdev->req_lock){+.+.}, at: [] hci_dev_do_close+0xfd/0xc50 net/bluetooth/hci_core.c:1576 #1: (&hdev->lock){+.+.}, at: [] hci_dev_do_close+0x210/0xc50 net/bluetooth/hci_core.c:1607 stack backtrace: CPU: 1 PID: 15309 Comm: syz-executor.4 Not tainted 4.14.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 start_flush_work kernel/workqueue.c:2861 [inline] flush_work+0x3ac/0x770 kernel/workqueue.c:2892 __cancel_work_timer+0x321/0x460 kernel/workqueue.c:2964 hci_conn_del+0x43/0x620 net/bluetooth/hci_conn.c:575 hci_conn_hash_flush+0x189/0x220 net/bluetooth/hci_conn.c:1377 hci_dev_do_close+0x542/0xc50 net/bluetooth/hci_core.c:1620 hci_unregister_dev+0x170/0x7a0 net/bluetooth/hci_core.c:3191 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa08/0x27f0 kernel/exit.c:865 do_group_exit+0x100/0x2e0 kernel/exit.c:962 get_signal+0x38d/0x1ca0 kernel/signal.c:2423 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45d5b9 RSP: 002b:00007fcb36459cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000118cfe8 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118cfe8 RBP: 000000000118cfe0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec R13: 00007ffe6424d8cf R14: 00007fcb3645a9c0 R15: 000000000118cfec device bond20 entered promiscuous mode bond20 (unregistering): Released all slaves device bond20 entered promiscuous mode nla_parse: 6 callbacks suppressed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. bond20 (unregistering): Released all slaves netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device bond20 entered promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. bond20 (unregistering): Released all slaves netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device bond20 entered promiscuous mode bond20 (unregistering): Released all slaves netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device bond20 entered promiscuous mode netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. bond20 (unregistering): Released all slaves netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. device bond20 entered promiscuous mode bond20 (unregistering): Released all slaves device bond20 entered promiscuous mode bond20 (unregistering): Released all slaves rxrpc: AF_RXRPC: Leaked local ffff88808b8984c0 {1} netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. ------------[ cut here ]------------ kernel BUG at net/rxrpc/local_object.c:408! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 22 Comm: kworker/u4:1 Not tainted 4.14.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net task: ffff8880a9a5a5c0 task.stack: ffff8880a9a60000 RIP: 0010:rxrpc_destroy_all_locals+0xe6/0xf2 net/rxrpc/local_object.c:408 RSP: 0018:ffff8880a9a67c28 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: ffff88809f0a18c0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ffff88809f0a18e0 R08: ffff8880aeb2beb0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809f0a18e0 R13: ffff88809f0a18f0 R14: dffffc0000000000 R15: fffffbfff10fe50f FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 00000000829f3000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rxrpc_exit_net+0x158/0x260 net/rxrpc/net_ns.c:78 device bond20 entered promiscuous mode ops_exit_list+0xa5/0x150 net/core/net_namespace.c:142 cleanup_net+0x3b3/0x840 net/core/net_namespace.c:484 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 00 00 00 00 00 fc ff df 48 83 eb 20 e8 84 ee 8b fb 4c 8d 63 20 4c 39 e5 0f 85 52 00 00 00 e8 72 ee 8b fb 4c 89 ef e8 ea 1f 84 00 <0f> 0b 48 89 ef e8 d0 b9 b5 fb eb c0 e8 59 ee 8b fb 48 c7 c7 60 RIP: rxrpc_destroy_all_locals+0xe6/0xf2 net/rxrpc/local_object.c:408 RSP: ffff8880a9a67c28 bond20 (unregistering): Released all slaves netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. ---[ end trace 95bd237bfe4e270a ]---