INFO: task syz.0.1745:17722 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1745 state:D stack:26896 pid:17722 tgid:17720 ppid:12822 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821
nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
__sys_sendmsg+0x160/0x210 net/socket.c:2770
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f11ae99de99
RSP: 002b:00007f11af819028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f11aec26090 RCX: 00007f11ae99de99
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000002
RBP: 00007f11aea33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11aec26128 R14: 00007f11aec26090 R15: 00007ffcc5782648
Showing all locks held in the system:
2 locks held by ksoftirqd/1/23:
1 lock held by khungtaskd/31:
#0: ffffffff8ebe7f80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8ebe7f80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8ebe7f80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz.3.358/8040:
#0: ffff88805a935880 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff88805a935880 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:709
#1: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: raw_release+0x1f3/0xc10 net/can/raw.c:430
2 locks held by getty/17281:
#0: ffff8880365a90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002e8a2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
2 locks held by syz.0.1745/17721:
#0: ffffffff90b50e28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f0716a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.0.1745/17722:
#0: ffffffff90b50e28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f0716a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.1.1877/18742:
#0: ffffffff90b50e28 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f0716a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
4 locks held by kworker/u10:3/19424:
#0: ffff88801ce92140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc900074ffd08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffff8880370aa0d8 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:566
#3: ffff8880370a8c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2571
5 locks held by kworker/u10:5/19439:
#0: ffff88801caf6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc900052c7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff90a89548 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x90/0xc10 net/core/dev.c:13085
#4: ffffffff8ebf3a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by kworker/u10:6/19463:
#0: ffff88801f32d140 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc90002eefd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
2 locks held by syz.3.2197/20970:
#0: ffff88803217c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88803217c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88803217c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88803217c0d8 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0716a0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.4.2205/21027:
#0: ffffffff90a89548 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1149
2 locks held by syz.5.2206/21032:
#0: ffffffff90a89548 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1149
2 locks held by syz.5.2206/21033:
#0: ffffffff90a89548 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:4017
2 locks held by syz.5.2206/21035:
#0: ffffffff90a89548 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#1: ffffffff90aa2140 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2103
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
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: 21023 Comm: syz.2.2207 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:check_preemption_disabled+0x1c/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d d5 55 ab 08 65 f7 05 c6 55 ab 08 ff ff ff 7f 74 0f <48> 83 c4 08 89 d8 5b 5d 41 5c c3 cc cc cc cc 9c 58 f6 c4 02 74 ea
RSP: 0018:ffffc9000402ebb8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffffffff81b803bd RSI: ffffffff8c400900 RDI: ffffffff8c400940
RBP: ffffc9000402ecb0 R08: 000000002fb9b5d8 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: ffffffff81f3d740
R13: ffffc9000402ec68 R14: 0000000000000000 R15: ffff888012c15d00
FS: 0000000000000000(0000) GS:ffff888123ee3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b346aaff8 CR3: 000000005b09a000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x6fa/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_unref_folios+0xa44/0x1710 mm/page_alloc.c:3011
folios_put_refs+0x585/0xaa0 mm/swap.c:1057
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1159
shmem_truncate_range mm/shmem.c:1287 [inline]
shmem_evict_inode+0x3a5/0xbe0 mm/shmem.c:1417
evict+0x3c2/0xad0 fs/inode.c:825
iput_final fs/inode.c:2019 [inline]
iput.part.0+0x989/0x1050 fs/inode.c:2068
iput+0x35/0x40 fs/inode.c:2034
dentry_unlink_inode+0x284/0x470 fs/dcache.c:479
dentry_kill+0x25d/0xc20 fs/dcache.c:826
shrink_kill fs/dcache.c:1275 [inline]
shrink_dentry_list+0x1e8/0x310 fs/dcache.c:1292
shrink_dcache_tree+0x201/0x400 fs/dcache.c:1759
do_one_tree fs/dcache.c:1795 [inline]
shrink_dcache_for_umount+0x101/0x6c0 fs/dcache.c:1812
generic_shutdown_super+0x7e/0x360 fs/super.c:625
kill_anon_super+0x3a/0x60 fs/super.c:1238
deactivate_locked_super+0xc1/0x1b0 fs/super.c:477
deactivate_super fs/super.c:510 [inline]
deactivate_super+0xe7/0x110 fs/super.c:506
cleanup_mnt+0x21f/0x450 fs/namespace.c:1317
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x951/0x2ae0 kernel/exit.c:1009
do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x652/0x840 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f15bd19de99
Code: Unable to access opcode bytes at 0x7f15bd19de6f.
RSP: 002b:00007f15be094028 EFLAGS: 00000246 ORIG_RAX: 00000000000000ed
RAX: 0000000000000000 RBX: 00007f15bd425fa0 RCX: 00007f15bd19de99
RDX: 0000000000000004 RSI: 00000000002091d2 RDI: 0000000000000000
RBP: 00007f15bd233eaf R08: 0000000000000006 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f15bd426038 R14: 00007f15bd425fa0 R15: 00007ffd4da58158