INFO: task syz.3.3394:16495 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3394 state:D stack:25128 pid:16495 ppid:12811 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6701 schedule+0xbd/0x170 kernel/sched/core.c:6775 perf_pending_task_sync kernel/events/core.c:5236 [inline] _free_event+0x176/0xfb0 kernel/events/core.c:5242 put_event kernel/events/core.c:5370 [inline] perf_event_release_kernel+0x7c8/0x850 kernel/events/core.c:5495 perf_release+0x3b/0x40 kernel/events/core.c:5505 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:890 do_group_exit+0x22d/0x2f0 kernel/exit.c:1032 get_signal+0x12a6/0x1390 kernel/signal.c:2911 arch_do_signal_or_restart+0xc2/0x7b0 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+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5fa759e0d9 RSP: 002b:00007f5fa83d4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: 0000000000000012 RBX: 00007f5fa7825fa0 RCX: 00007f5fa759e0d9 RDX: 0000000000000012 RSI: 00002000000001c0 RDI: 000000000000000a RBP: 00007f5fa7635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5fa7826038 R14: 00007f5fa7825fa0 R15: 00007ffc33abc198 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5536: #0: ffff88803154a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 2 locks held by kworker/1:3/5782: #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #1: ffffc900046ffd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc900046ffd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 1 lock held by syz.4.3848/18076: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.5.3849/18079: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 5 locks held by syz.5.3849/18080: 2 locks held by syz.2.3851/18085: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 2 locks held by syz.0.3852/18088: #0: ffffffff97341c70 (&pmus_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:116 [inline] #0: ffffffff97341c70 (&pmus_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:215 [inline] #0: ffffffff97341c70 (&pmus_srcu){.+.+}-{0:0}, at: perf_init_event kernel/events/core.c:11882 [inline] #0: ffffffff97341c70 (&pmus_srcu){.+.+}-{0:0}, at: perf_event_alloc+0xb23/0x2150 kernel/events/core.c:12203 #1: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x50/0x2d0 kernel/trace/trace_event_perf.c:221 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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+0xf59/0xfa0 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: 18080 Comm: syz.5.3849 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:memory_is_nonzero mm/kasan/generic.c:101 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x6a/0x290 mm/kasan/generic.c:187 Code: 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 4d 89 f4 <4d> 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 4c 89 cb 48 RSP: 0018:ffffc90000007988 EFLAGS: 00000803 RAX: 0000000000000001 RBX: dffffc0000000001 RCX: ffffffff81694414 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb508 RBP: 0000000000000001 R08: ffffffff911eb50f R09: 1ffffffff223d6a1 R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: fffffbfff223d6a2 R13: dffffc0000000000 R14: fffffbfff223d6a2 R15: 1ffffffff223d6a1 FS: 00007f79133ff6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcaca027dac CR3: 0000000064502000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] mark_lock+0x94/0x320 kernel/locking/lockdep.c:4656 mark_usage kernel/locking/lockdep.c:4555 [inline] __lock_acquire+0xc5c/0x7d80 kernel/locking/lockdep.c:5091 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 seqcount_lockdep_reader_access+0xd1/0x1d0 include/linux/seqlock.h:102 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get_update_offsets_now+0x99/0x3f0 kernel/time/timekeeping.c:2320 hrtimer_update_base kernel/time/hrtimer.c:654 [inline] hrtimer_interrupt+0x11e/0x980 kernel/time/hrtimer.c:1862 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:deref_stack_reg+0x13/0x230 arch/x86/kernel/unwind_orc.c:402 Code: c3 23 a4 00 48 8b 4c 24 18 e9 c1 fe ff ff 66 0f 1f 84 00 00 00 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 54 24 10 <48> 89 34 24 49 89 ff 48 bd 00 00 00 00 00 fc ff df e8 37 a1 4b 00 RSP: 0018:ffffc90003956aa8 EFLAGS: 00000292 RAX: fffffffffffffff0 RBX: ffffffff8fad9b25 RCX: 0000000000000003 RDX: ffffc90003956c08 RSI: ffffc90003957f48 RDI: ffffc90003956bc8 RBP: ffffc90003956c18 R08: ffff888031945a00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000002 R12: ffffc90003957f20 R13: ffffc90003956bc8 R14: ffffffff8fad9b24 R15: dffffc0000000000 unwind_next_frame+0x1781/0x2990 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 skb_kfree_head net/core/skbuff.c:946 [inline] skb_free_head net/core/skbuff.c:958 [inline] skb_release_data+0x609/0x7f0 net/core/skbuff.c:988 skb_release_all net/core/skbuff.c:1054 [inline] __kfree_skb net/core/skbuff.c:1068 [inline] kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1104 kfree_skb include/linux/skbuff.h:1264 [inline] ____dev_forward_skb include/linux/netdevice.h:4073 [inline] __dev_forward_skb2+0x546/0x770 net/core/dev.c:2225 veth_forward_skb drivers/net/veth.c:323 [inline] veth_xmit+0x42e/0xa30 drivers/net/veth.c:378 __netdev_start_xmit include/linux/netdevice.h:4945 [inline] netdev_start_xmit include/linux/netdevice.h:4959 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454 __bond_start_xmit include/linux/netdevice.h:-1 [inline] bond_start_xmit+0xe9f/0x1be0 drivers/net/bonding/bond_main.c:5581 __netdev_start_xmit include/linux/netdevice.h:4945 [inline] netdev_start_xmit include/linux/netdevice.h:4959 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454 dev_queue_xmit include/linux/netdevice.h:3115 [inline] __bpf_tx_skb+0x181/0x260 net/core/filter.c:2154 ____bpf_clone_redirect net/core/filter.c:2489 [inline] bpf_clone_redirect+0x315/0x4a0 net/core/filter.c:2452 bpf_prog_ef75413035540f6e+0x21/0x25 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:617 [inline] bpf_prog_run include/linux/filter.h:624 [inline] bpf_test_run+0x2df/0x870 net/bpf/test_run.c:424 bpf_prog_test_run_skb+0xdbb/0x18f0 net/bpf/test_run.c:1089 bpf_prog_test_run+0x31f/0x390 kernel/bpf/syscall.c:4132 __sys_bpf+0x49d/0x890 kernel/bpf/syscall.c:5496 __do_sys_bpf kernel/bpf/syscall.c:5582 [inline] __se_sys_bpf kernel/bpf/syscall.c:5580 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f791259e0d9 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:00007f79133ff028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f7912825fa0 RCX: 00007f791259e0d9 RDX: 0000000000000050 RSI: 00002000000003c0 RDI: 000000000000000a RBP: 00007f7912635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7912826038 R14: 00007f7912825fa0 R15: 00007ffc56b50e48