INFO: task syz.1.1690:11197 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1690 state:D stack:23848 pid:11197 ppid:5777 flags:0x00004002 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: 0033:0x7f00fdd9e019 RSP: 002b:00007f00fec73028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 0000000000000011 RBX: 00007f00fe026090 RCX: 00007f00fdd9e019 RDX: 000000000000275a RSI: 0000200000000040 RDI: 000000000000000f RBP: 00007f00fde3500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f00fe026128 R14: 00007f00fe026090 R15: 00007fffe6c905d8 Showing all locks held in the system: 3 locks held by kworker/u4:0/11: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9952 [inline] #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x19e/0x730 kernel/events/core.c:9990 #2: ffff8880b8f295d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x6cf/0xd60 kernel/time/timer.c:1112 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 4 locks held by kworker/u4:3/49: #0: ffff88801a25c938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801a25c938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90000b9fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90000b9fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3c9b10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606 #3: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: sit_exit_batch_net+0xdd/0x4f0 net/ipv6/sit.c:1888 1 lock held by dhcpcd/5436: #0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2fc/0x1d70 net/ipv4/devinet.c:1101 2 locks held by getty/5535: #0: ffff8880317d20a0 (&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+0x428/0x1370 drivers/tty/n_tty.c:2217 2 locks held by kworker/0:3/5767: #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+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc900045f7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc900045f7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 3 locks held by kworker/u4:6/11734: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90004e4fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90004e4fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by syz.3.1991/12501: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 2 locks held by syz.3.1991/12502: #0: ffffffff8dbf92a8 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xe0/0x1ac0 drivers/net/ppp/ppp_generic.c:739 #1: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3363 [inline] #1: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1073 [inline] #1: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xa68/0x1ac0 drivers/net/ppp/ppp_generic.c:743 2 locks held by syz.6.1992/12503: #0: ffff88805c7be820 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff88805c7be820 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff88805c7be820 (&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:324 [inline] #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by syz.0.1993/12513: #0: ffffffff8d188088 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 ============================================= 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 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: 3463 Comm: kworker/u4:11 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: bat_events batadv_nc_worker RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [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+0x7f/0x290 mm/kasan/generic.c:187 Code: 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> f7 d3 4c 01 fb 41 80 3b 00 0f 85 8d 01 00 00 49 ff c3 48 ff c3 RSP: 0018:ffffc9000c82f788 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 1ffffffff223d6a0 RCX: ffffffff8168908b RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911eb500 RBP: ffffc9000c82fa08 R08: ffffffff911eb507 R09: 1ffffffff223d6a0 R10: dffffc0000000000 R11: fffffbfff223d6a0 R12: 0000000000000001 R13: ffff88802e560000 R14: fffffbfff223d6a1 R15: 1ffffffff223d6a0 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110e22fff6 CR3: 0000000062047000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 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] check_wait_context kernel/locking/lockdep.c:4774 [inline] __lock_acquire+0x61b/0x7d80 kernel/locking/lockdep.c:5087 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] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x600 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811 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