INFO: task syz.2.18128:27903 blocked for more than 143 seconds. Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.18128 state:D stack:21784 pid:27903 tgid:27900 ppid:26208 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 nfsd_nl_rpc_status_get_dumpit+0xdc/0x1a60 fs/nfsd/nfsctl.c:1516 genl_dumpit+0x10d/0x1b0 net/netlink/genetlink.c:1027 netlink_dump+0x64d/0xe10 net/netlink/af_netlink.c:2318 __netlink_dump_start+0x5a2/0x790 net/netlink/af_netlink.c:2433 genl_family_rcv_msg_dumpit net/netlink/genetlink.c:1076 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline] genl_rcv_msg+0x88c/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:728 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2568 ___sys_sendmsg net/socket.c:2622 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2654 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff129d8cda9 RSP: 002b:00007ff127bf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff129fa5fa0 RCX: 00007ff129d8cda9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 00007ff129e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff129fa5fa0 R15: 00007fff92f6b928 Showing all locks held in the system: 2 locks held by kworker/u8:0/11: #0: ffff88801cf35148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801cf35148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90000107c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000107c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 1 lock held by khungtaskd/30: #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/u8:7/3439: #0: ffff88801cf35148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801cf35148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9000cc0fc60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000cc0fc60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 2 locks held by getty/5581: #0: ffff888035af20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5827: #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8ec02d48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:596 2 locks held by kworker/u8:5/22733: #0: ffff88801cf35148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801cf35148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9001b95fc60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9001b95fc60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 2 locks held by syz-executor/9437: #0: ffff888054b8c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888054b8c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888054b8c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8ec02d48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:596 2 locks held by syz.6.17585/25376: #0: ffffffff8fd11bb0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec02d48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1922 3 locks held by syz.2.18128/27903: #0: ffffffff8fd11bb0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88805bd666c8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2397 #2: ffffffff8ec02d48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1a60 fs/nfsd/nfsctl.c:1516 3 locks held by kworker/0:0/29219: #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90003527c60 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003527c60 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #2: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996 1 lock held by syz.8.19142/32239: #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz.8.19142/32242: #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803463c0e0 (&type->s_umount_key#88){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 51 Comm: kworker/1:1 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:149 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:256 [inline] RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:212 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc f3 0f 1e fa 89 f6 31 d2 e9 e3 9a af 03 0f 1f RSP: 0018:ffffc90000a18e60 EFLAGS: 00000046 RAX: 000000000001f6da RBX: 0000000000000020 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000001f6da RDI: 0000000000000838 RBP: 000000000001f6da R08: ffffffff81affd59 R09: 1ffffffff20344ee R10: dffffc0000000000 R11: ffffffff81691480 R12: 00000000001f6cfa R13: dffffc0000000000 R14: 00000000100058eb R15: ffff8880b8728340 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e008ff8 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:405 [inline] lapic_next_event+0x11/0x20 arch/x86/kernel/apic/apic.c:415 clockevents_program_event+0x1c1/0x350 kernel/time/clockevents.c:334 hrtimer_interrupt+0x5b7/0xa40 kernel/time/hrtimer.c:1940 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x700/0xa10 kernel/printk/printk.c:2431 Code: 00 e8 e4 d3 20 00 4c 8d bc 24 a0 00 00 00 4d 85 e4 75 07 e8 d2 d3 20 00 eb 06 e8 cb d3 20 00 fb 49 bc 00 00 00 00 00 fc ff df <48> c7 c7 80 43 81 8e 31 f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 RSP: 0018:ffffc90000bb78a0 EFLAGS: 00000293 RAX: ffffffff819e89f5 RBX: 0000000000000000 RCX: ffff8880222c5a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000bb79b0 R08: ffffffff819e89ce R09: 1ffffffff285873a R10: dffffc0000000000 R11: fffffbfff285873b R12: dffffc0000000000 R13: 1ffff92000176f18 R14: ffffffff819e8830 R15: ffffc90000bb7940 _printk+0xd5/0x120 kernel/printk/printk.c:2457 m920x_rc_core_query+0x2c8/0x510 dvb_usb_read_remote_control+0xb8/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244