INFO: task syz.1.8489:28855 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.8489 state:D stack:24816 pid:28855 ppid: 21869 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f74a8068eb9 RSP: 002b:00007f74a62a30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f74a82e4098 RCX: 00007f74a8068eb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f74a82e4098 RBP: 00007f74a82e4090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f74a82e4128 R14: 00007ffd2795a2c0 R15: 00007ffd2795a3a8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by udevd/3561: 2 locks held by getty/3950: #0: ffff88802cab7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by kworker/1:11/5195: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900038efd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/0:11/5283: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90003c0fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 3 locks held by kworker/0:0/18220: 3 locks held by kworker/u4:16/28099: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000384fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 2 locks held by kworker/1:3/29817: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900034dfd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/1:4/29922: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000387fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by syz.7.9288/31880: 2 locks held by syz.7.9293/31896: 2 locks held by syz.5.9306/31933: 1 lock held by syz.2.9308/31939: #0: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 3 locks held by syz.2.9308/31942: #0: ffffffff8d498f10 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802 #1: ffffffff8d498d68 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8d498d68 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x161/0xf90 net/netlink/genetlink.c:790 #2: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_register_hw+0x2441/0x3af0 net/mac80211/main.c:1251 2 locks held by syz.5.9310/31944: #0: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.8.9311/31955: #0: ffffffff8d43c548 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x700 net/netlink/af_netlink.c:2352 2 locks held by dhcpcd/31960: #0: ffff8880745f5010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff8880745f5010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline] #0: ffff8880745f5010 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 1 lock held by dhcpcd/31961: #0: ffff888079c2a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff888079c2a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/31962: #0: ffff88801f946120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88801f946120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 ============================================= 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+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3543 Comm: syslogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rcu_lock_acquire+0x11/0x30 include/linux/rcupdate.h:313 Code: 89 f6 48 89 da 5b 41 5e 41 5f e9 4a f3 fc ff 66 2e 0f 1f 84 00 00 00 00 00 e8 cb 33 f3 ff e8 c6 33 f3 ff 48 c7 c7 a0 ea 31 8c <31> f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 68 d5 eb 85 81 e8 26 RSP: 0018:ffffc900012df438 EFLAGS: 00000293 RAX: ffffffff8185ebda RBX: 00007f3ca9b16407 RCX: ffff88807e7e8000 RDX: 0000000000000000 RSI: ffffffff8a79f760 RDI: ffffffff8c31eaa0 RBP: 0000000000022a01 R08: 0000000000000004 R09: 000000000000000d R10: dffffc0000000000 R11: fffff5200025bea5 R12: ffff88807e7e8000 R13: ffff888079a90400 R14: 00007f3ca9b16407 R15: 1ffff9200025bea2 FS: 00007f3ca99c6c80(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556667315a30 CR3: 000000002b733000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: rcu_read_lock include/linux/rcupdate.h:740 [inline] is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x6b8/0x800 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb+0xa2/0x100 net/core/skbuff.c:914 skb_free_datagram+0x25/0xe0 net/core/datagram.c:325 __unix_dgram_recvmsg+0xa01/0xd90 net/unix/af_unix.c:2395 sock_recvmsg_nosec net/socket.c:968 [inline] sock_recvmsg net/socket.c:986 [inline] sock_read_iter+0x2b8/0x380 net/socket.c:1067 call_read_iter include/linux/fs.h:2167 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x759/0xd60 fs/read_write.c:485 ksys_read+0x152/0x260 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3ca9b16407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffddbfcf520 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f3ca99c6c80 RCX: 00007f3ca9b16407 RDX: 00000000000000ff RSI: 000055de9cfe2950 RDI: 0000000000000000 RBP: 000055de9cfe2910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055de9cfe29a1 R13: 0000000000000000 R14: 000055de9cfe2950 R15: 000055de84c74d98