INFO: task syz-executor.2:26091 blocked for more than 143 seconds. Not tainted 5.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28328 26091 6979 0x80004006 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1f90 kernel/sched/core.c:4156 schedule+0xd0/0x2a0 kernel/sched/core.c:4231 rwsem_down_write_slowpath+0x706/0xf90 kernel/locking/rwsem.c:1235 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1844 bcm_release+0x8b/0x660 net/can/bcm.c:1474 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1278 __fput+0x33e/0x880 fs/file_table.c:281 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb3f/0x2de0 kernel/exit.c:806 do_group_exit+0x125/0x340 kernel/exit.c:904 get_signal+0x47b/0x24e0 kernel/signal.c:2739 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:810 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca59 Code: Bad RIP value. RSP: 002b:00007f3902e88c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000003 RBX: 0000000000507820 RCX: 000000000045ca59 RDX: 0000000000000002 RSI: 0000000000000002 RDI: 000000000000001d RBP: 000000000078c220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000b97 R14: 00000000004cdf53 R15: 00007f3902e896d4 Showing all locks held in the system: 3 locks held by kworker/u4:7/453: #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:279 [inline] #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88821b039138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc900018e7dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 #2: ffffffff8a586130 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:565 1 lock held by khungtaskd/1149: #0: ffffffff899be040 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 1 lock held by in:imklog/6490: #0: ffff888097d9fb70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.2/26091: #0: ffff888025bd6750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline] #0: ffff888025bd6750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604 #1: ffffffff8a586130 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1844 1 lock held by syz-executor.2/26464: #0: ffffffff8a586130 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x270/0x590 net/core/net_namespace.c:478 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1149 Comm: khungtaskd Not tainted 5.7.0-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 31224 Comm: kworker/u4:1 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:90 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:183 [inline] RIP: 0010:check_memory_region+0xc9/0x190 mm/kasan/generic.c:192 Code: 38 00 74 ed 4c 8d 40 08 eb 09 48 83 c0 01 49 39 c0 74 69 80 38 00 74 f2 49 89 c0 b8 01 00 00 00 4d 85 c0 75 61 5b 5d 41 5c c3 <4d> 85 c9 74 4d 49 01 d9 eb 09 48 83 c0 01 4c 39 c8 74 3f 80 38 00 RSP: 0018:ffffc9001c45f9c0 EFLAGS: 00000083 RAX: fffffbfff1863b4c RBX: fffffbfff1863b4c RCX: ffffffff8159769f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8c31da60 RBP: fffffbfff1863b4d R08: 0000000000000006 R09: 0000000000000001 R10: ffffffff8c31da67 R11: fffffbfff1863b4c R12: 0000000000000004 R13: ffff88801c7a8500 R14: ffff88801c7a8dd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee5c026000 CR3: 00000000a8e78000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] check_wait_context kernel/locking/lockdep.c:4079 [inline] __lock_acquire+0x76f/0x4a70 kernel/locking/lockdep.c:4330 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4959 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:358 [inline] batadv_nc_purge_paths+0xdf/0x380 net/batman-adv/network-coding.c:441 batadv_nc_worker+0x2c6/0x760 net/batman-adv/network-coding.c:721 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351