INFO: task syz.4.5:4447 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.5 state:D stack:24192 pid:4447 ppid:4313 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 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:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9d4098f749 RSP: 002b:00007f9d3ebd4fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff4 RBX: 00007f9d40be6090 RCX: 00007f9d4098f749 RDX: 00002000000000c0 RSI: 0000200000000a50 RDI: 0000000000000400 RBP: 00007f9d40a13f91 R08: 0000200000000ac0 R09: 0000200000000ac0 R10: 0000200000000a80 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f9d40be6128 R14: 00007f9d40be6090 R15: 00007ffe00febc98 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (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: ffffffff8cb2be50 (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/28: #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by kworker/1:2/3043: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000d627d00 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:107 [inline] #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_masks_rebalance+0x2b/0xd0 net/openvswitch/datapath.c:2504 3 locks held by kworker/0:3/3598: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000e797d00 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:107 [inline] #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_masks_rebalance+0x2b/0xd0 net/openvswitch/datapath.c:2504 2 locks held by getty/4027: #0: ffff88814d08b098 (&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 3 locks held by kworker/1:3/4326: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004077d00 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:107 [inline] #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_masks_rebalance+0x2b/0xd0 net/openvswitch/datapath.c:2504 3 locks held by kworker/0:5/4377: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004317d00 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:107 [inline] #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_masks_rebalance+0x2b/0xd0 net/openvswitch/datapath.c:2504 2 locks held by kworker/1:5/4393: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004807d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/u4:5/4401: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900048afd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 3 locks held by kworker/0:9/4449: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000491fd00 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:107 [inline] #2: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_masks_rebalance+0x2b/0xd0 net/openvswitch/datapath.c:2504 1 lock held by syz.6.819/7527: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492 2 locks held by syz.3.822/7536: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492 #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 1 lock held by syz.1.823/7544: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492 1 lock held by syz.1.823/7546: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 1 lock held by syz.1.823/7547: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 1 lock held by syz.1.823/7555: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: wext_ioctl_dispatch+0xaf/0x470 net/wireless/wext-core.c:996 3 locks held by syz.2.825/7554: #0: ffffffff8dda1570 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_lock net/openvswitch/datapath.c:107 [inline] #1: ffffffff8e057e68 (ovs_mutex){+.+.}-{3:3}, at: ovs_dp_cmd_new+0x65b/0xa80 net/openvswitch/datapath.c:1812 #2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: internal_dev_create+0x3a7/0x570 net/openvswitch/vport-internal_dev.c:158 2 locks held by syz.0.829/7572: 2 locks held by syz.0.830/7574: #0: ffffffff8dd43c08 (bpf_dispatcher_xdp.mutex){+.+.}-{3:3}, at: bpf_dispatcher_change_prog+0x9d/0xcc0 kernel/bpf/dispatcher.c:146 #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 ============================================= 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 10/02/2025 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7572 Comm: syz.0.829 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:try_charge_memcg+0x1/0x17f0 mm/memcontrol.c:2632 Code: 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 34 c0 f8 ff 4c 89 f7 41 ff 17 e9 30 ff ff ff 66 0f 1f 84 00 00 00 00 00 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 00 02 00 RSP: 0018:ffffc900049fec50 EFLAGS: 00000287 RAX: dffffc0000000000 RBX: ffffea0001224740 RCX: ffffffff81d7f967 RDX: 0000000000000001 RSI: 0000000000000cc0 RDI: ffff88807ad8c000 RBP: ffffc900049fed10 R08: dffffc0000000000 R09: fffff940002448e9 R10: fffff940002448e9 R11: 1ffffd40002448e8 R12: 0000000000000001 R13: 1ffffd40002448e8 R14: ffff88807ad8c000 R15: 0000000000000cc0 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2407b7198 CR3: 0000000023c5c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00002000000000c0 DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: try_charge mm/memcontrol.c:2826 [inline] charge_memcg+0x113/0x380 mm/memcontrol.c:6923 __mem_cgroup_charge+0x21/0x80 mm/memcontrol.c:6944 mem_cgroup_charge include/linux/memcontrol.h:672 [inline] shmem_add_to_page_cache+0x8fc/0x1c00 mm/shmem.c:708 shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556 generic_perform_write+0x2db/0x560 mm/filemap.c:3846 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x3ea/0x7f0 fs/coredump.c:977 elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 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 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fe24044f6b7 Code: 88 15 42 60 ec 00 88 05 3f 60 ec 00 c3 50 48 8d 35 e9 48 1c 00 48 8d 3d ef 48 1c 00 31 c0 e8 20 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007fe2414d0120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fe24058f749 RDX: 00007fe2414d0140 RSI: 00007fe2414d0270 RDI: 000000000000000b RBP: 00007fe240613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000d40 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fe2407e6128 R14: 00007fe2407e6090 R15: 00007fff3e5e7408