INFO: task syz-executor.2:11995 can't die for more than 143 seconds. task:syz-executor.2 state:D stack:28152 pid:11995 ppid: 8439 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4329 [inline] __schedule+0x917/0x2170 kernel/sched/core.c:5079 schedule+0xcf/0x270 kernel/sched/core.c:5158 rwsem_down_write_slowpath+0x7dc/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1407 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 bcm_release+0x94/0x780 net/can/bcm.c:1474 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x41926b RSP: 002b:00007ffce520f0f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 000000000041926b RDX: 0000000000570730 RSI: 000000000d187dae RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b33220ddc R10: 00007ffce520f1e0 R11: 0000000000000293 R12: 000000000005ac69 R13: 00000000000003e8 R14: 000000000056bf60 R15: 000000000005ac31 INFO: task syz-executor.2:11995 blocked for more than 143 seconds. Not tainted 5.12.0-rc6-next-20210409-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:28152 pid:11995 ppid: 8439 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4329 [inline] __schedule+0x917/0x2170 kernel/sched/core.c:5079 schedule+0xcf/0x270 kernel/sched/core.c:5158 rwsem_down_write_slowpath+0x7dc/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1407 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 bcm_release+0x94/0x780 net/can/bcm.c:1474 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x41926b RSP: 002b:00007ffce520f0f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 000000000041926b RDX: 0000000000570730 RSI: 000000000d187dae RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b33220ddc R10: 00007ffce520f1e0 R11: 0000000000000293 R12: 000000000005ac69 R13: 00000000000003e8 R14: 000000000056bf60 R15: 000000000005ac31 Showing all locks held in the system: 4 locks held by kworker/u4:6/284: #0: ffff88814018b138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814018b138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88814018b138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88814018b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88814018b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88814018b138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc9000182fda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d67de10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:557 #3: ffffffff8bf7e370 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x430 kernel/rcu/tree.c:3996 1 lock held by khungtaskd/1649: #0: ffffffff8bf752a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 2 locks held by in:imklog/8127: #0: ffff88802499b770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 #1: ffffffff8bf64218 (syslog_lock){....}-{2:2}, at: is_bpf_text_address+0x0/0x170 kernel/bpf/core.c:691 2 locks held by agetty/8359: #0: ffff888026249098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90000f1d2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd5b/0x12f0 drivers/tty/n_tty.c:2178 2 locks held by syz-executor.2/11995: #0: ffff888032249c50 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff888032249c50 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:598 #1: ffffffff8d67de10 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1949 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1649 Comm: khungtaskd Not tainted 5.12.0-rc6-next-20210409-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd3b/0xf50 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4848 Comm: systemd-journal Not tainted 5.12.0-rc6-next-20210409-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:unwind_next_frame+0x829/0x1ce0 arch/x86/kernel/unwind_orc.c:466 Code: 83 e0 07 40 38 c6 40 0f 9e c7 40 84 f6 0f 95 c0 40 84 c7 0f 85 bc 0f 00 00 49 0f bf 30 48 01 d6 48 89 74 24 60 e9 d8 fd ff ff <48> b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc9000150f608 EFLAGS: 00000297 RAX: 0000000000000005 RBX: 1ffff920002a1ec9 RCX: ffffffff8e3fccc7 RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8e3fccc2 R09: ffffffff8e3fccc2 R10: fffff520002a1ef1 R11: 0000000000084087 R12: ffffc9000150f778 R13: ffffc9000150f765 R14: ffffc9000150f730 R15: ffffffff8e3fccc6 FS: 00007f7a5c01f8c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7a594be000 CR3: 00000000294b7000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x51b/0x800 arch/x86/kernel/unwind_orc.c:699 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0x5c/0xe0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345 task_work_add+0x3a/0x190 kernel/task_work.c:38 fput_many.part.0+0xbb/0x170 fs/file_table.c:341 fput_many fs/file_table.c:336 [inline] fput+0x3b/0x50 fs/file_table.c:357 path_openat+0x19a3/0x27d0 fs/namei.c:3503 do_filp_open+0x190/0x3d0 fs/namei.c:3521 do_sys_openat2+0x16d/0x420 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1207 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7a5b5ae840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffd95b146d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffd95b149e0 RCX: 00007f7a5b5ae840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055965f4b71a0 RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 000055965f4aa040 R14: 00007ffd95b149a0 R15: 000055965f4b6fc0