INFO: task syz-executor.3:24974 blocked for more than 143 seconds. Not tainted 5.8.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28472 24974 7040 0xa0024006 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4155 schedule+0xd0/0x2a0 kernel/sched/core.c:4230 rwsem_down_write_slowpath+0x603/0xc60 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:1855 raw_release+0x58/0x890 net/can/raw.c:354 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1278 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb72/0x2a40 kernel/exit.c:805 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x428/0x1fc0 kernel/signal.c:2739 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:212 [inline] __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:246 __do_fast_syscall_32 arch/x86/entry/common.c:448 [inline] do_fast_syscall_32+0x7f/0x120 arch/x86/entry/common.c:474 entry_SYSENTER_compat+0x6d/0x7c arch/x86/entry/entry_64_compat.S:138 RIP: 0023:0xf7fc0569 Code: Bad RIP value. RSP: 002b:00000000f5d9a0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000167 RAX: 0000000000000004 RBX: 000000000000001d RCX: 0000000000000003 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:0/7: 1 lock held by khungtaskd/1143: #0: ffffffff89bbe640 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 1 lock held by in:imklog/6604: #0: ffff8880989068f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 4 locks held by kworker/1:0/15086: #0: ffff8880ae735e18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1261 [inline] #0: ffff8880ae735e18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x22d/0x1eb0 kernel/sched/core.c:4101 #1: ffffffff89bbe640 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1051 [inline] #1: ffffffff89bbe640 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x3e0 kernel/sched/fair.c:6002 #2: ffffffff8cbad288 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:955 [inline] #2: ffffffff8cbad288 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0xc7/0x41c lib/debugobjects.c:998 #3: ffffffff8cb80438 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:636 2 locks held by syz-executor.3/24974: #0: ffff888023985c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline] #0: ffff888023985c90 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release+0x86/0x280 net/socket.c:604 #1: ffffffff8a7a3630 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1855 1 lock held by syz-executor.3/25055: #0: ffffffff8a7a3630 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2ac/0x5e0 net/core/net_namespace.c:478 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1143 Comm: khungtaskd Not tainted 5.8.0-rc2-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 28324 Comm: kworker/0:218 Not tainted 5.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:rdrand_long arch/x86/include/asm/archrandom.h:25 [inline] RIP: 0010:arch_get_random_long arch/x86/include/asm/archrandom.h:75 [inline] RIP: 0010:arch_get_random_long arch/x86/include/asm/archrandom.h:73 [inline] RIP: 0010:_extract_crng+0xee/0x250 drivers/char/random.c:1008 Code: 7d fd 4c 8d 7d 48 4c 89 ff e8 6e 91 f1 03 48 89 04 24 0f 1f 44 00 00 e8 30 9b 7d fd bb 0a 00 00 00 e8 26 9b 7d fd 49 0f c7 f4 <41> 0f 92 c5 31 ff 44 89 ee e8 54 97 7d fd 45 84 ed 0f 85 e6 00 00 RSP: 0018:ffffc9000d6cfb10 EFLAGS: 00000003 RAX: 0000000000000000 RBX: 000000000000000a RCX: ffffffff815a9580 RDX: ffff88801f1e00c0 RSI: ffffffff83f5b5ca RDI: ffffc9000d6cfa80 RBP: ffff88809e4a3100 R08: 0000000000000001 R09: 0000000000000003 R10: fffff52001ad9f50 R11: 0000000000000000 R12: 1b72a98d549f009d R13: ffffc9000d6cfb98 R14: ffffc9000d6cfb98 R15: ffff88809e4a3148 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd10dcd3018 CR3: 0000000094148000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: extract_crng drivers/char/random.c:1026 [inline] _get_random_bytes+0x229/0x6d0 drivers/char/random.c:1562 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:527 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:557 [inline] nsim_dev_trap_report_work+0x759/0xbe0 drivers/net/netdevsim/dev.c:598 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293