INFO: task syz.1.1283:9613 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1283 state:D stack:25800 pid:9613 ppid:5771 flags:0x00004002 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:5242 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5248 put_event kernel/events/core.c:5376 [inline] perf_event_release_kernel+0x842/0x8d0 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+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 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: 0033:0x7fd64df9c799 RSP: 002b:00007fd64edd7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000016 RBX: 00007fd64e216090 RCX: 00007fd64df9c799 RDX: 0000000000000106 RSI: 0200000000000001 RDI: 0000000000000002 RBP: 00007fd64e032bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd64e216128 R14: 00007fd64e216090 R15: 00007ffc5a7b7c88 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:11/3467: #0: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffc9000cc97d00 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000cc97d00 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 1 lock held by udevd/5140: 2 locks held by getty/5529: #0: ffff888031a590a0 (&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+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by kworker/0:3/5759: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc9000445fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000445fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 3 locks held by kworker/u4:7/11191: 5 locks held by syz.0.2152/12260: 1 lock held by syz.0.2167/12310: #0: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 2 locks held by syz.3.2174/12327: #0: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12260 Comm: syz.0.2152 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4820 [inline] RIP: 0010:__lock_acquire+0xbcf/0x7d40 kernel/locking/lockdep.c:5087 Code: c1 fe ff ff 48 c7 c7 70 13 8b 8e e8 0b 13 77 00 49 b8 00 00 00 00 00 fc ff df e9 a6 fe ff ff 8b 84 24 88 00 00 00 38 44 24 38 <4c> 8b 6c 24 20 4c 8b 7c 24 10 76 38 e8 40 d6 bd 02 49 b8 00 00 00 RSP: 0018:ffffc9000cc6f080 EFLAGS: 00000097 RAX: 0000000000000002 RBX: 0000000000000003 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911bf500 RBP: ffffc9000cc6f2c8 R08: dffffc0000000000 R09: 1ffffffff2237ea0 R10: dffffc0000000000 R11: fffffbfff2237ea1 R12: 0000000000000002 R13: ffff888023c86578 R14: ffffffff90b29eca R15: ffff888023c86578 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd10bde82f8 CR3: 0000000076116000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] page_ext_get+0x3e/0x2b0 mm/page_ext.c:508 page_table_check_clear+0x4a/0x6a0 mm/page_table_check.c:74 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] zap_pte_range mm/memory.c:1429 [inline] zap_pmd_range mm/memory.c:1571 [inline] zap_pud_range mm/memory.c:1600 [inline] zap_p4d_range mm/memory.c:1621 [inline] unmap_page_range+0x1ad9/0x3000 mm/memory.c:1642 unmap_vmas+0x286/0x3f0 mm/memory.c:1732 exit_mmap+0x238/0xb90 mm/mmap.c:3302 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1f2/0x2c0 kernel/exit.c:569 do_exit+0x8dd/0x2460 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 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 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f2766f9c7a1 Code: Unable to access opcode bytes at 0x7f2766f9c777. RSP: 002b:0000000000002100 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f2767215fa0 RCX: 00007f2766f9c799 RDX: 0000200000000000 RSI: 0000000000002100 RDI: 0000000080001000 RBP: 00007f2767032bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f2767216038 R14: 00007f2767215fa0 R15: 00007ffe357b4678