INFO: task syz.1.4986:21548 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.4986 state:D stack:23504 pid:21548 ppid:14543 flags:0x00004006 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 get_signal+0x118d/0x1340 kernel/signal.c:2649 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: 0033:0x7fc1dc59de99 RSP: 002b:00007fc1dd39bfd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007fc1dc826090 RCX: 00007fc1dc59de99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040100000 RBP: 00007fc1dc633eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fc1dc826128 R14: 00007fc1dc826090 R15: 00007ffcc44b8788 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/27: #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 4 locks held by udevd/3636: #0: ffff8880b8f3ad18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:538 #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9736 [inline] #1: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x184/0x6d0 kernel/events/core.c:9774 #2: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #2: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #2: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: dput+0x37/0x1d0 fs/dcache.c:904 #3: ffff8880236a6c68 (&dentry->d_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff8880236a6c68 (&dentry->d_lock){+.+.}-{2:2}, at: lockref_put_or_lock+0x22/0xb0 lib/lockref.c:147 2 locks held by getty/4021: #0: ffff88814cbd7098 (&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 3 locks held by kworker/u4:7/4391: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90002e87d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff88813fe94618 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x5a/0x10b0 kernel/sched/core.c:4112 2 locks held by kworker/0:3/12235: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90006617d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 1 lock held by syz.5.5661/23865: #0: ffffffff8cb33700 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5e0 kernel/rcu/tree.c:4023 2 locks held by syz.5.5661/23868: 2 locks held by syz.6.5659/23871: 2 locks held by syz.6.5667/23886: #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 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 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: 23868 Comm: syz.5.5661 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0xdc/0x4a0 kernel/locking/lockdep.c:5647 Code: 2f bd 0c 0f 83 a2 01 00 00 45 89 f4 41 c1 ee 06 4a 8d 3c f5 a8 21 21 8e be 08 00 00 00 e8 2c 55 6f 00 4c 0f a3 25 ac 2d bd 0c <73> 0d e8 ad 2e 08 00 84 c0 0f 84 2e 02 00 00 48 c7 c0 64 56 21 8e RSP: 0018:ffffc900001e0d00 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8163f3f4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e2121a8 RBP: ffffc900001e0e08 R08: ffffffff8e2121af R09: 1ffffffff1c42435 R10: dffffc0000000000 R11: fffffbfff1c42436 R12: 0000000000000001 R13: 1ffff9200003c1ac R14: 0000000000000000 R15: dffffc0000000000 FS: 00007fdec85d56c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc6759eb580 CR3: 0000000033def000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: fffffffffffffffc DR3: fffffffffffffffc DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 hrtimer_interrupt+0xf4/0x980 kernel/time/hrtimer.c:1858 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:347 [inline] RIP: 0010:deref_stack_reg+0x64/0x220 arch/x86/kernel/unwind_orc.c:357 Code: 9a 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 48 89 5c 24 08 49 8b 6f 08 49 8d 7f 10 49 89 fd 49 c1 ed 03 41 80 7c 35 00 00 <74> 13 e8 b5 2c 9a 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 4d RSP: 0018:ffffc90005096c18 EFLAGS: 00000246 RAX: fffffffffffffff0 RBX: ffffc90005096d48 RCX: 0000000000000000 RDX: ffffc90005096d48 RSI: dffffc0000000000 RDI: ffffc90005096d18 RBP: ffffc90005090000 R08: ffffc90005097d70 R09: ffffc90005096d58 R10: dffffc0000000000 R11: fffff52000a12dad R12: 1ffff92000a12da2 R13: 1ffff92000a12da3 R14: ffffc90005096d40 R15: ffffc90005096d08 unwind_next_frame+0x15fc/0x1fd0 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_krealloc+0xfd/0x1a0 mm/kasan/common.c:443 kasan_krealloc include/linux/kasan.h:231 [inline] __do_krealloc mm/slab_common.c:1332 [inline] krealloc+0xc1/0x100 mm/slab_common.c:1369 copy_array kernel/bpf/verifier.c:955 [inline] copy_stack_state kernel/bpf/verifier.c:1009 [inline] copy_func_state kernel/bpf/verifier.c:1130 [inline] copy_verifier_state+0x67a/0xae0 kernel/bpf/verifier.c:1166 pop_stack kernel/bpf/verifier.c:1201 [inline] do_check kernel/bpf/verifier.c:12728 [inline] do_check_common+0x89ba/0xc560 kernel/bpf/verifier.c:14943 do_check_main kernel/bpf/verifier.c:15006 [inline] bpf_check+0x3ea7/0x11000 kernel/bpf/verifier.c:15583 bpf_prog_load+0x100e/0x1530 kernel/bpf/syscall.c:2651 __sys_bpf+0x5b8/0x780 kernel/bpf/syscall.c:5031 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline] __se_sys_bpf kernel/bpf/syscall.c:5133 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdeca39de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdec85d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fdeca626090 RCX: 00007fdeca39de99 RDX: 0000000000000048 RSI: 0000200000000200 RDI: 0000000000000005 RBP: 00007fdeca433eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdeca626128 R14: 00007fdeca626090 R15: 00007ffc0fd5ef28