INFO: task syz.1.1209:9269 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1209 state:D stack:26504 pid:9269 ppid:5770 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: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 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 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd69c99cdd9 RSP: 002b:00007fd69d933f38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fd69ca09420 RCX: 00007fd69c99cdd9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 000000000000000e R08: 0000000000000000 R09: 00007fd69cc16038 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007fd69cc16038 R14: 00007fd69cc15fa0 R15: 00007ffefbb9c7d8 Showing all locks held in the system: 1 lock held by rcu_tasks_trace/15: #0: ffffffff8d132e10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0xadb/0xdb0 kernel/rcu/tasks.h:607 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/5531: #0: ffff88814cd760a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by kworker/0:3/5778: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000465fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000465fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 3 locks held by kworker/u4:26/8911: #0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000ba17d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000ba17d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8e3b5a90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606 1 lock held by syz.0.2025/11962: #0: ffffffff8e3b5a90 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516 1 lock held by syz.4.2026/11964: #0: ffffffff8d192328 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x8b/0x310 kernel/trace/bpf_trace.c:2215 ============================================= 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: 11940 Comm: syz.0.2017 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:in_irqentry_text kernel/stacktrace.c:379 [inline] RIP: 0010:filter_irq_stacks+0x5f/0x90 kernel/stacktrace.c:395 Code: 89 ff e8 14 8b 69 00 49 8b 04 de 48 3d e0 01 a0 8a 0f 93 c1 48 3d f0 15 a0 8a 0f 92 c2 84 d1 75 27 48 3d 70 3b 90 8a 0f 92 c1 <48> 3d 7b 3b 90 8a 0f 93 c0 08 c8 74 11 48 ff c3 49 83 c7 08 49 39 RSP: 0018:ffffc90011c7ef78 EFLAGS: 00000287 RAX: ffffffff812e4792 RBX: 000000000000000f RCX: 0000000000000001 RDX: 0000000000002801 RSI: 0000000000000010 RDI: ffffc90011c7f040 RBP: 0000000000002800 R08: ffffc90011c7ef90 R09: 000000000000000f R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000010 R13: dffffc0000000000 R14: ffffc90011c7f040 R15: ffffc90011c7f0b8 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86c2fea2f8 CR3: 000000002d1fc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __stack_depot_save+0x1f/0x630 lib/stackdepot.c:377 save_stack+0x133/0x230 mm/page_owner.c:129 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2504 release_pages+0x1f7a/0x2200 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x630/0x1b20 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x245/0x9e0 mm/shmem.c:1264 evict+0x4ca/0x8d0 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5e5/0x970 fs/file_table.c:392 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 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: 0033:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 002b:00002000000001c8 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f5288c15fa0 RCX: 00007f528899cdd9 RDX: 0000200000000240 RSI: 00002000000001c0 RDI: 0000000040188000 RBP: 00007f5288a32d69 R08: 00002000000002c0 R09: 00002000000002c0 R10: 0000200000000140 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f5288c16038 R14: 00007f5288c15fa0 R15: 00007ffc51d06518