INFO: task syz-executor.0:10694 can't die for more than 143 seconds. task:syz-executor.0 state:D stack:29400 pid:10694 ppid: 8448 flags:0x00004004 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 register_netdevice_notifier+0x1e/0x260 net/core/dev.c:1902 isotp_init+0x452/0x530 net/can/isotp.c:1381 can_create+0x27c/0x4d0 net/can/af_can.c:168 __sock_create+0x353/0x790 net/socket.c:1408 sock_create net/socket.c:1459 [inline] __sys_socketpair+0x242/0x570 net/socket.c:1563 __do_sys_socketpair net/socket.c:1612 [inline] __se_sys_socketpair net/socket.c:1609 [inline] __x64_sys_socketpair+0x93/0xf0 net/socket.c:1609 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 RSP: 002b:00007f42e35e2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000006 RSI: 0000000000000002 RDI: 000000000000001d RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000380 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd8d1d4a5f R14: 00007f42e35e2300 R15: 0000000000022000 INFO: task syz-executor.0:10694 blocked for more than 143 seconds. Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:29400 pid:10694 ppid: 8448 flags:0x00004004 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 register_netdevice_notifier+0x1e/0x260 net/core/dev.c:1902 isotp_init+0x452/0x530 net/can/isotp.c:1381 can_create+0x27c/0x4d0 net/can/af_can.c:168 __sock_create+0x353/0x790 net/socket.c:1408 sock_create net/socket.c:1459 [inline] __sys_socketpair+0x242/0x570 net/socket.c:1563 __do_sys_socketpair net/socket.c:1612 [inline] __se_sys_socketpair net/socket.c:1609 [inline] __x64_sys_socketpair+0x93/0xf0 net/socket.c:1609 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 RSP: 002b:00007f42e35e2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000006 RSI: 0000000000000002 RDI: 000000000000001d RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000380 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd8d1d4a5f R14: 00007f42e35e2300 R15: 0000000000022000 Showing all locks held in the system: 3 locks held by kworker/u4:1/25: #0: ffff88814017b138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814017b138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88814017b138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88814017b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88814017b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88814017b138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x1600 kernel/workqueue.c:2246 #1: ffffc90000dffda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1600 kernel/workqueue.c:2250 #2: ffffffff8d681250 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:557 1 lock held by khungtaskd/1651: #0: ffffffff8bf76560 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6333 1 lock held by in:imklog/8132: #0: ffff8880212dc0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.0/10694: #0: ffffffff8d681250 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1e/0x260 net/core/dev.c:1902 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1651 Comm: khungtaskd Not tainted 5.12.0-rc7-next-20210415-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: 188 Comm: kworker/u4:4 Not tainted 5.12.0-rc7-next-20210415-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:match_held_lock+0xa/0x150 kernel/locking/lockdep.c:4964 Code: 80 3d e4 6f a2 04 00 74 01 c3 48 c7 c7 a0 a1 6b 89 c6 05 d3 6f a2 04 01 e8 50 f1 be ff 0f 0b c3 48 39 77 10 0f 84 97 00 00 00 <66> f7 47 22 f0 ff 74 4b 48 83 ec 08 48 8b 46 08 48 85 c0 0f 84 84 RSP: 0018:ffffc900011bfaf0 EFLAGS: 00000083 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bf764a0 RDI: ffff888012ac42f8 RBP: ffffffff8bf764a0 R08: 0000000000000000 R09: ffffffff8dc80e0f R10: fffffbfff1b901c1 R11: 0000000000000000 R12: ffff888012ac3900 R13: ffff888012ac42f8 R14: 00000000ffffffff R15: ffff888012ac42f8 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff1ca4c9000 CR3: 00000000307a4000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5255 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5555 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5523 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x12/0x30 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:404 [inline] batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:467 batadv_nc_worker+0x7ff/0xe50 net/batman-adv/network-coding.c:716 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294