INFO: task syz.1.1274:9525 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1274 state:D stack:22568 pid:9525 ppid:5775 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 get_signal+0x11da/0x1390 kernel/signal.c:2687 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: 0033:0x7f7536b9e0d9 RSP: 002b:00007f75379fafd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f7536e25fa0 RCX: 00007f7536b9e0d9 RDX: 0000200000002700 RSI: 00002000000026f0 RDI: 0000000048200000 RBP: 00007f7536c35024 R08: 0000200000002780 R09: 0000200000002780 R10: 0000200000002740 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f7536e26038 R14: 00007f7536e25fa0 R15: 00007ffe73cd9e78 Showing all locks held in the system: 1 lock held by khungtaskd/29: #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 kworker/u4:4/78: #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #1: ffffc900015b7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc900015b7d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 2 locks held by kworker/0:3/2177: #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: ffffc9000539fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc9000539fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 2 locks held by getty/5533: #0: ffff88814cc270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032832f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 1 lock held by syz.0.1929/11353: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.2.1932/11361: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 2 locks held by syz.2.1932/11362: 2 locks held by syz.4.1934/11365: #0: ffff88805c4c2020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff88805c4c2020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff88805c4c2020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1421 #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.3.1935/11367: #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:324 [inline] #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/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 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11362 Comm: syz.2.1932 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4798 [inline] RIP: 0010:__lock_acquire+0x952/0x7d80 kernel/locking/lockdep.c:5087 Code: 97 01 00 00 41 8b 07 41 89 c6 41 81 e6 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 f5 1e 91 be 08 00 00 00 e8 ce 5d 77 00 <4c> 0f a3 35 16 61 b6 0f 73 1a 49 69 c6 d0 00 00 00 4c 8d b0 c0 73 RSP: 0018:ffffc9000b776ae0 EFLAGS: 00000056 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816893e2 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911ef500 RBP: ffffc9000b776d28 R08: ffffffff911ef507 R09: 1ffffffff223dea0 R10: dffffc0000000000 R11: fffffbfff223dea1 R12: 0000000000000000 R13: ffff88802d2be508 R14: 0000000000000021 R15: ffff88802d2be508 FS: 00007fc2375e56c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e33d7eff8 CR3: 000000007997a000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300 DR3: 0000200000000300 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] is_bpf_text_address+0x47/0x2a0 kernel/bpf/core.c:742 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 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_add_bulk net/core/skbuff.c:1125 [inline] kfree_skb_list_reason+0x264/0x460 net/core/skbuff.c:1147 __dev_xmit_skb net/core/dev.c:3955 [inline] __dev_queue_xmit+0x1f87/0x3640 net/core/dev.c:4434 dev_queue_xmit include/linux/netdevice.h:3157 [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_dde6c29962cc7727+0x5e/0x63 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: 0033:0x7fc23679e0d9 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:00007fc2375e5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fc236a25fa0 RCX: 00007fc23679e0d9 RDX: 0000000000000050 RSI: 0000200000000100 RDI: 000000000000000a RBP: 00007fc236835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc236a26038 R14: 00007fc236a25fa0 R15: 00007fffb4bab9a8