INFO: task syz.0.10212:5165 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.10212 state:D stack:23016 pid:5165 ppid:3261 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5244 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5250 put_event kernel/events/core.c:5378 [inline] perf_event_release_kernel+0x842/0x8d0 kernel/events/core.c:5503 perf_release+0x3b/0x40 kernel/events/core.c:5513 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 get_signal+0x1235/0x13f0 kernel/signal.c:2678 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdd3539cdd9 RSP: 002b:00007fdd361b9fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffff RBX: 00007fdd35616090 RCX: 00007fdd3539cdd9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002c9a4080 RBP: 00007fdd35432d69 R08: ffffffffff600000 R09: ffffffffff600000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fdd35616128 R14: 00007fdd35616090 R15: 00007ffe13955c88 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5529: #0: ffff8880326b00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 3 locks held by kworker/u4:25/19989: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19978 Comm: kworker/u4:14 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4773 [inline] RIP: 0010:__lock_acquire+0x57b/0x7d40 kernel/locking/lockdep.c:5087 Code: 81 e3 ff 1f 00 00 41 c1 ef 03 41 81 e7 f8 03 00 00 49 8d bf 00 55 1c 91 be 08 00 00 00 e8 4d 26 77 00 48 0f a3 1d f5 1f b4 0f <73> 1f 48 69 c3 d0 00 00 00 48 8d 98 c0 d3 b2 90 48 ba 00 00 00 00 RSP: 0018:ffffc9000467f4e0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 000000000000002f RCX: ffffffff81683503 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911c5500 RBP: ffffc9000467f728 R08: ffffffff911c5507 R09: 1ffffffff2238aa0 R10: dffffc0000000000 R11: fffffbfff2238aa1 R12: ffff888059220ac4 R13: ffff888059220000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a15d473660 CR3: 00000000270d3000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] crng_make_state+0x15f/0x700 drivers/char/random.c:340 _get_random_bytes+0x100/0x250 drivers/char/random.c:378 eth_random_addr include/linux/etherdevice.h:232 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:756 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x368/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293