INFO: task syz.0.4636:18664 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.4636 state:D stack:25264 pid:18664 ppid:11750 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x176/0x1050 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9bcdd9de59 RSP: 002b:00007f9bcec5c028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffea RBX: 00007f9bce025fa0 RCX: 00007f9bcdd9de59 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000014c0 RBP: 00007f9bcde33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9bce026038 R14: 00007f9bce025fa0 R15: 00007ffe83257ad8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527 2 locks held by getty/4029: #0: ffff88802ff77098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 2 locks held by kworker/0:4/4318: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004107d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/u4:6/4332: 2 locks held by syz.6.5148/20327: #0: ffffffff8dd4bd90 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8cb33700 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5e0 kernel/rcu/tree.c:4023 1 lock held by syz.2.5154/20347: #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 2 locks held by syz.5.5161/20354: #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 1 lock held by syz.1.5162/20356: #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 2 locks held by syz.4.5163/20362: #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline] #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 20352 Comm: syz.2.5154 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:116 [inline] RIP: 0010:lock_release+0xef/0x920 kernel/locking/lockdep.c:5689 Code: ab bc 0c 73 0d e8 a1 ac 07 00 84 c0 0f 84 41 05 00 00 48 c7 c0 64 56 21 8e 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 49 05 00 00 <83> 3d 2e e0 bc 0c 00 0f 84 a6 04 00 00 65 8b 05 7d 03 9e 7e 85 c0 RSP: 0018:ffffc900033272e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 8e2212e4e3a08d00 RDX: 0000000000000000 RSI: ffffffff8adf42c0 RDI: ffffffff8adf4280 RBP: ffffc900033273e8 R08: ffffffff8e2121af R09: 1ffffffff1c42435 R10: dffffc0000000000 R11: fffffbfff1c42436 R12: dffffc0000000000 R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff92000664e68 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f421ff8 CR3: 000000002e67b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:904 [inline] pfn_valid+0x3c5/0x420 include/linux/mmzone.h:1867 page_table_check_clear+0x1e/0x6b0 mm/page_table_check.c:67 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] zap_pte_range mm/memory.c:1433 [inline] zap_pmd_range mm/memory.c:1572 [inline] zap_pud_range mm/memory.c:1601 [inline] zap_p4d_range mm/memory.c:1622 [inline] unmap_page_range+0x1905/0x25b0 mm/memory.c:1643 unmap_vmas+0x260/0x390 mm/memory.c:1728 exit_mmap+0x20d/0x970 mm/mmap.c:3250 __mmput+0x118/0x3a0 kernel/fork.c:1206 exit_mm+0x24d/0x350 kernel/exit.c:566 do_exit+0x958/0x2570 kernel/exit.c:868 do_group_exit+0x229/0x2e0 kernel/exit.c:1024 get_signal+0x1259/0x1340 kernel/signal.c:2872 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 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:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7feb5c39de59 Code: Unable to access opcode bytes at 0x7feb5c39de2f. RSP: 002b:00007feb5d3090e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007feb5c626098 RCX: 00007feb5c39de59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007feb5c626098 RBP: 00007feb5c626090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb5c626128 R14: 00007ffea0804d70 R15: 00007ffea0804e58