INFO: task syz.3.645:9538 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.645 state:D stack:26344 pid:9538 tgid:9535 ppid:5873 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2614 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668 __sys_sendmsg+0x16d/0x220 net/socket.c:2700 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06f9d8ebe9 RSP: 002b:00007f06fac87038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f06f9fc5fa0 RCX: 00007f06f9d8ebe9 RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000004 RBP: 00007f06f9e11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f06f9fc6038 R14: 00007f06f9fc5fa0 R15: 00007ffe6f612718 Showing all locks held in the system: 2 locks held by kworker/u8:1/13: #0: ffff888144aef148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000127d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 1 lock held by khungtaskd/31: #0: ffffffff8e5c10e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c10e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c10e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: 2 locks held by getty/5630: #0: ffff88803512e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5864: #0: ffff88805f1160e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805f1160e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805f1160e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88805f1160e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/5868: #0: ffff88805ab000e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805ab000e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805ab000e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88805ab000e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 6 locks held by kworker/u8:11/6329: 2 locks held by syz.0.641/9511: #0: ffffffff9042b710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919 2 locks held by syz.3.645/9538: #0: ffffffff9042b710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629 2 locks held by syz-executor/9850: #0: ffff888028bfa0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888028bfa0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888028bfa0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff888028bfa0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz-executor/9963: #0: ffff88804902e0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88804902e0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88804902e0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff88804902e0e0 (&type->s_umount_key#50){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by syz.5.855/10813: #0: ffffffff9042b710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919 2 locks held by syz.5.855/10820: #0: ffffffff9042b710 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e9d97c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919 1 lock held by syz.8.945/11391: 1 lock held by syz.9.943/11393: 1 lock held by syz-executor/11502: #0: ffffffff8e5cc678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by syz.9.971/11538: #0: ffffffff90371f50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:566 #1: ffffffff8e5cc678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11391 Comm: syz.8.945 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:rol32 include/linux/bitops.h:126 [inline] RIP: 0010:iterate_chain_key kernel/locking/lockdep.c:451 [inline] RIP: 0010:__lock_acquire+0x68b/0x1ce0 kernel/locking/lockdep.c:5225 Code: c8 c1 c2 06 41 31 d6 44 89 f2 44 29 f1 41 01 c6 c1 c2 08 31 d1 89 ca 29 c8 44 01 f1 c1 c2 10 89 cf 31 d0 89 c6 41 29 c6 01 c8 ce 0d 44 31 f6 89 f2 29 f7 01 f0 c1 c2 04 89 c0 31 fa 48 c1 e2 RSP: 0018:ffffc90018467b70 EFLAGS: 00000096 RAX: 00000000fce9ec55 RBX: ffff88802d0b64f0 RCX: 00000000fce6dfbe RDX: 000000000316fcea RSI: 0000000000030c97 RDI: 00000000fce6dfbe RBP: 0000000000000000 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88802d0b64f0 R13: ffff88802d0b5a00 R14: 00000000fff9d011 R15: 0000000000000003 FS: 00007f044297a6c0(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000035f000 CR3: 000000008a15a000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] mousedev_write+0x1b4/0x850 drivers/input/mousedev.c:686 vfs_write+0x29d/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0441b8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f044297a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0441dc6090 RCX: 00007f0441b8ebe9 RDX: 000000100000a3d9 RSI: 0000200000000b00 RDI: 0000000000000002 RBP: 00007f0441c11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0441dc6128 R14: 00007f0441dc6090 R15: 00007ffe889437c8