INFO: task syz.4.4002:19915 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.4002 state:D stack:23424 pid:19915 ppid:19566 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x10ec/0x40b0 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+0x171/0x10a0 kernel/events/core.c:5037
put_event kernel/events/core.c:5162 [inline]
perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287
perf_release+0x37/0x40 kernel/events/core.c:5297
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1ca/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x93e/0x2400 kernel/exit.c:880
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb7/0x1240 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: 0033:0x7f7165b8f749
RSP: 002b:00007f71669b30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7165de5fa8 RCX: 00007f7165b8f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7165de5fa8
RBP: 00007f7165de5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7165de6038 R14: 00007ffde154de60 R15: 00007ffde154df48
Showing all locks held in the system:
6 locks held by kworker/u4:1/11:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db2f310 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x66/0x490 net/caif/caif_dev.c:527
#4: ffff88802e601380 (&caifn->caifdevs.lock){+.+.}-{3:3}, at: caif_exit_net+0x79/0x490 net/caif/caif_dev.c:528
#5: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#5: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bb70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92c390 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4028:
#0: ffff88802feda098 (&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+0x41b/0x1380 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:5/4318:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004867d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
3 locks held by kworker/0:7/4376:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004b9fd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8c930d80 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023
2 locks held by kworker/u4:40/12442:
#0: ffff8880b8f3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:538
#1: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9706 [inline]
#1: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x13c/0x630 kernel/events/core.c:9744
2 locks held by syz.0.4425/21652:
1 lock held by syz.9.4426/21654:
#0: ffffffff8c980268 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
1 lock held by syz.9.4426/21665:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
2 locks held by syz.6.4427/21657:
#0: ffff888043992610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#0: ffff888043992610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
#0: ffff888043992610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1399
#1: ffff88807bdcbfb0 (sk_lock-AF_PHONET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#1: ffff88807bdcbfb0 (sk_lock-AF_PHONET){+.+.}-{0:0}, at: pep_sock_unhash+0x26/0x2e0 net/phonet/pep.c:1326
7 locks held by syz.6.4427/21658:
1 lock held by syz.6.4427/21666:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104
1 lock held by syz.8.4429/21664:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: do_ip_setsockopt+0x425/0x2d60 net/ipv4/ip_sockglue.c:954
1 lock held by syz.0.4430/21670:
#0: ffffffff8c980268 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
1 lock held by syz.0.4430/21671:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
3 locks held by syz.0.4430/21673:
#0: ffff888073c21410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
#0: ffff888073c21410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline]
#0: ffff888073c21410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1399
#1: ffff888144241270 (sk_lock-AF_QIPCRTR){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#1: ffff888144241270 (sk_lock-AF_QIPCRTR){+.+.}-{0:0}, at: qrtr_release+0x4e/0x2a0 net/qrtr/af_qrtr.c:1208
#2: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#2: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 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 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 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+0xeee/0xf30 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: 21664 Comm: syz.8.4429 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:check_preemption_disabled+0x56/0x110 lib/smp_processor_id.c:19
Code: 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 74 cc 65 4c 8b 3d 96 2d f1 75 41 f6
RSP: 0018:ffffc90004117380 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8a6c12e0 RDI: ffffffff8abefec0
RBP: ffffc900041174d8 R08: dffffc0000000000 R09: fffffbfff1bfe48e
R10: fffffbfff1bfe48e R11: 1ffffffff1bfe48d R12: 0000000000000001
R13: 1ffff92000822e84 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa18b9b6ad8 CR3: 000000007e675000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline]
lock_acquire+0x17a/0x490 kernel/locking/lockdep.c:5661
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351
__mem_cgroup_uncharge_list+0x6c/0xc0 mm/memcontrol.c:7140
mem_cgroup_uncharge_list include/linux/memcontrol.h:699 [inline]
release_pages+0x1f8a/0x2200 mm/swap.c:1034
tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
tlb_flush_mmu+0xff/0x210 mm/mmu_gather.c:261
tlb_finish_mmu+0xbd/0x1c0 mm/mmu_gather.c:361
exit_mmap+0x343/0x8e0 mm/mmap.c:3262
__mmput+0x118/0x3c0 kernel/fork.c:1205
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb7/0x1240 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: 0033:0x7f9f98d8f749
Code: Unable to access opcode bytes at 0x7f9f98d8f71f.
RSP: 002b:00007f9f99bab038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffea RBX: 00007f9f98fe5fa0 RCX: 00007f9f98d8f749
RDX: 000000000000002d RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f9f98e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9f98fe6038 R14: 00007f9f98fe5fa0 R15: 00007ffc35355078