INFO: task syz.1.3481:14530 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.1.3481 state:D stack:28136 pid:14530 tgid:14526 ppid:5627 task_flags:0x400040 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_get_doit+0x13f/0x7c0 fs/nfsd/nfsctl.c:2114
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: 0033:0x7fdcc419de99
RSP: 002b:00007fdcc4f91028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdcc4426090 RCX: 00007fdcc419de99
RDX: 0000000000000050 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007fdcc4233eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdcc4426128 R14: 00007fdcc4426090 R15: 00007fff12eca2e8
Showing all locks held in the system:
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
3 locks held by kworker/0:2/187:
#0: ffff88801bc0b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc9000241fd08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff8ebf38f8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3857
4 locks held by kworker/u8:6/667:
#0: ffff88801caf6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297
#1: ffffc900042afd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffffffff90a89188 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff90aa1d80 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff90aa1d80 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
3 locks held by kworker/u8:9/1120:
#0: ffff8880b853b660 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:667
#1: ffffc90005777d08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298
#2: ffff8880b8526298 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x124/0x1d0 kernel/time/timer.c:1004
2 locks held by getty/5383:
#0: ffff8880368c80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5624:
#0: ffff8880520bc0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880520bc0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880520bc0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880520bc0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0712e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.1.3481/14527:
#0: ffffffff90b50a68 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f0712e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.1.3481/14530:
#0: ffffffff90b50a68 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f0712e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x13f/0x7c0 fs/nfsd/nfsctl.c:2114
2 locks held by syz-executor/14645:
#0: ffff88807ef3e0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807ef3e0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807ef3e0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807ef3e0d8 (&type->s_umount_key#56){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8f0712e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
1 lock held by syz-executor/15279:
#0: ffffffff8ebf3a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.2.4401/17304:
#0: ffffffff8ebf3a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14003 Comm: syz.3.3283 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:_compound_head include/linux/page-flags.h:226 [inline]
RIP: 0010:PageMemcgKmem include/linux/memcontrol.h:515 [inline]
RIP: 0010:__free_pages_prepare mm/page_alloc.c:1329 [inline]
RIP: 0010:free_pages_prepare+0xe7/0xd80 mm/page_alloc.c:1451
Code: 89 de 4c 89 ef e8 29 1c ff ff 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 80 3c 02 00 0f 85 ee 0a 00 00 <4d> 8b 75 08 4c 89 f0 83 e0 01 48 83 e8 01 49 09 c6 48 b8 00 00 00
RSP: 0018:ffffc90002ddf878 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8269b041
RDX: 1ffffd400032fea1 RSI: ffffffff8c400900 RDI: ffffffff8e46c920
RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff224539a
R10: ffffffff91229cd7 R11: 0000000000000000 R12: ffffea000197f508
R13: ffffea000197f500 R14: ffffea000197f500 R15: ffffea000197f500
FS: 0000000000000000(0000) GS:ffff888123de3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f04fd39a0 CR3: 00000000363c2000 CR4: 00000000003526f0
Call Trace:
__free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
__free_contig_range mm/page_alloc.c:6942 [inline]
free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3439
vfree mm/vmalloc.c:3488 [inline]
vfree+0x107/0x750 mm/vmalloc.c:3462
kcov_put kernel/kcov.c:447 [inline]
kcov_put kernel/kcov.c:443 [inline]
kcov_close+0x34/0x60 kernel/kcov.c:554
__fput+0x3ff/0xb50 fs/file_table.c:512
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: 0033:0x7fe80179de99
Code: Unable to access opcode bytes at 0x7fe80179de6f.
RSP: 002b:00007fe8026b10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fe801a25fa8 RCX: 00007fe80179de99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe801a25fa8
RBP: 00007fe801a25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe801a26038 R14: 00007ffc5445a0a0 R15: 00007ffc5445a188