INFO: task syz.4.6757:26795 blocked for more than 143 seconds. Not tainted 6.6.102-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.6757 state:D stack:22632 pid:26795 ppid:25980 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 perf_pending_task_sync kernel/events/core.c:5242 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5248 put_event kernel/events/core.c:5376 [inline] perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5501 perf_release+0x3b/0x40 kernel/events/core.c:5511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 get_signal+0x1235/0x1400 kernel/signal.c:2678 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 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+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5d1a98ebe9 RSP: 002b:00007f5d18bf5fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f5d1abb5fa0 RCX: 00007f5d1a98ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007f5d1aa11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f5d1abb6038 R14: 00007f5d1abb5fa0 R15: 00007ffc062b33a8 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5548: #0: ffff88814ccad0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/0:3/18523: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000478fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000478fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff888060ef3240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491 4 locks held by kworker/u4:16/19093: #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90003cd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90003cd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfaec50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606 #3: ffffffff8cd35a80 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 3 locks held by syz.6.7060/27924: 1 lock held by syz.6.7067/27957: #0: ffffffff8cd35a80 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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: 27924 Comm: syz.6.7060 Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215 Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 3c ff c4 0c 48 89 de 5b e9 93 76 56 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d d0 2e 7e 7e 65 8b 15 d1 2e 7e 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc90003697418 EFLAGS: 00000202 RAX: ffffffff81e7ac66 RBX: 0000000000000001 RCX: ffff88807d1d1e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000050889 RBP: ffffc90003697650 R08: ffffea0001422207 R09: 1ffffd4000284440 R10: dffffc0000000000 R11: fffff94000284441 R12: 0000001b2de20000 R13: dffffc0000000000 R14: 0000000000050889 R15: 0000001b2de05000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5b44584198 CR3: 000000002c5b3000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: page_table_check_clear+0x16/0x6a0 mm/page_table_check.c:64 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] zap_pte_range mm/memory.c:1428 [inline] zap_pmd_range mm/memory.c:1570 [inline] zap_pud_range mm/memory.c:1599 [inline] zap_p4d_range mm/memory.c:1620 [inline] unmap_page_range+0x1ad1/0x2fe0 mm/memory.c:1641 unmap_vmas+0x25e/0x3a0 mm/memory.c:1731 exit_mmap+0x200/0xb50 mm/mmap.c:3298 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_general_protection+0x170/0x200 arch/x86/kernel/traps.c:745 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602 RIP: 0033:0x7f5b4438ebf1 Code: Unable to access opcode bytes at 0x7f5b4438ebc7. RSP: 002b:00002000000002b0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f5b445b6090 RCX: 00007f5b4438ebe9 RDX: 0000000000000000 RSI: 00002000000002b0 RDI: 0000000000000000 RBP: 00007f5b44411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5b445b6128 R14: 00007f5b445b6090 R15: 00007fff81bde568