INFO: task syz.1.1936:14817 blocked for more than 143 seconds. Tainted: G U syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1936 state:D stack:25688 pid:14817 tgid:14816 ppid:5827 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590 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+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4166b8efc9 RSP: 002b:00007f4164df6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4166de5fa0 RCX: 00007f4166b8efc9 RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000006 RBP: 00007f4166c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4166de6038 R14: 00007f4166de5fa0 R15: 00007fff357d4c48 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/10732: #0: ffff88814d0260a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000af8e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz.2.1892/14631: #0: ffffffff9018dad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ece88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880 2 locks held by syz.1.1936/14817: #0: ffffffff9018dad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ece88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590 2 locks held by syz-executor/14923: #0: ffff8880824280e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880824280e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880824280e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff8880824280e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ece88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz.0.2031/15249: #0: ffff888024b2a0e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888024b2a0e0 (&type->s_umount_key#50){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888024b2a0e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888024b2a0e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7ece88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:593 2 locks held by syz.3.2191/16048: #0: ffffffff9018dad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ece88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1590 2 locks held by syz.5.2336/16805: #0: ffffffff9018dad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7ece88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1880 2 locks held by syz.8.2454/17359: 3 locks held by syz-executor/17616: #0: ffffffff900e9f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900e9f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff900e9f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064 #1: ffff888049874d38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2765 [inline] #1: ffff888049874d38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888049874d38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:39 [inline] #1: ffff888049874d38 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: do_setlink.constprop.0+0x2e9/0x4380 net/core/rtnetlink.c:3061 #2: ffffffff8e3cf878 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 3 locks held by syz.7.2514/17656: 2 locks held by syz.9.2522/17696: #0: ffffffff900d3af0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576 #1: ffffffff8e3cf740 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3820 2 locks held by syz.9.2522/17704: #0: ffffffff900d3af0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576 #1: ffffffff8e3cf740 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3820 2 locks held by syz.7.2526/17709: #0: ffffffff900d3af0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576 #1: ffffffff900e9f08 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x64/0x3c0 net/caif/caif_dev.c:528 2 locks held by syz.6.2531/17727: #0: ffffffff900d3af0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x2d6/0x690 net/core/net_namespace.c:576 #1: ffffffff900e9f08 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21d/0x7d0 net/ipv4/ip_tunnel.c:1146 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U syzkaller #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17359 Comm: syz.8.2454 Tainted: G U syzkaller #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:hlock_class+0x13/0x70 kernel/locking/lockdep.c:234 Code: 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f b7 47 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 2d d3 0f 14 <73> 15 48 8d 04 80 48 8d 04 80 48 8d 04 c5 a0 c9 a7 95 e9 16 25 c8 RSP: 0018:ffffc90003dcf888 EFLAGS: 00000003 RAX: 0000000000000007 RBX: 0000000000000001 RCX: 00000000bc86c441 RDX: 0000000000000000 RSI: 00000000dbc7214e RDI: ffff88807a65c7d8 RBP: ffff88807a65bc80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807a65c7b0 R13: ffff88807a65c7d8 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f8ad4a266c0(0000) GS:ffff888124a10000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001652000 CR3: 000000003be04000 CR4: 00000000003526f0 Call Trace: __lock_acquire+0x622/0x1c90 kernel/locking/lockdep.c:5234 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] mtree_load+0xef/0xa30 lib/maple_tree.c:5886 vma_lookup include/linux/mm.h:3536 [inline] do_pages_stat_array mm/migrate.c:2436 [inline] do_pages_stat+0x3db/0x7b0 mm/migrate.c:2506 kernel_move_pages+0xfc8/0x12f0 mm/migrate.c:2587 __do_sys_move_pages mm/migrate.c:2598 [inline] __se_sys_move_pages mm/migrate.c:2593 [inline] __x64_sys_move_pages+0xe0/0x1c0 mm/migrate.c:2593 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ad3b8efc9 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:00007f8ad4a26038 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 00007f8ad3de6090 RCX: 00007f8ad3b8efc9 RDX: 0000000000000000 RSI: 0002000000000003 RDI: 0000000000000034 RBP: 00007f8ad3c11f91 R08: 0000000000000000 R09: 8000400000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8ad3de6128 R14: 00007f8ad3de6090 R15: 00007fffe1fc4d38