INFO: task syz.4.3334:18289 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3334 state:D stack:27200 pid:18289 tgid:18288 ppid:15925 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 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+0x7bf/0x1550 kernel/locking/mutex.c:821
nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2114
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 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+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea7919de99
RSP: 002b:00007fea79fc0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fea79425fa0 RCX: 00007fea7919de99
RDX: 0000000020000090 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007fea79233eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fea79426038 R14: 00007fea79425fa0 R15: 00007fff0492fcd8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5383:
#0: ffff8880362580a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
1 lock held by udevd/7691:
#0: ffff888027f97350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948
1 lock held by udevd/7698:
#0: ffff888027e8f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948
2 locks held by syz.1.3237/17805:
#0: ffffffff9009d608 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964
2 locks held by syz.4.3334/18289:
#0: ffffffff9009d608 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2114
3 locks held by kworker/u8:47/18790:
#0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000ff6fc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000ff6fc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8eb5fe38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
3 locks held by kworker/u8:49/18794:
#0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#1: ffffc9000ffbfc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
#1: ffffc9000ffbfc40 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
#2: ffffffff8eb5fe38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3857
2 locks held by syz.0.3483/19009:
#0: ffffffff9009d608 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ee8e5e0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_cache_flush_doit+0xb5/0x1b0 fs/nfsd/nfsctl.c:2236
2 locks held by syz.7.4578/23303:
#0: ffff88804d831380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff88804d831380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:709 [inline]
#0: ffff88804d831380 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1501
#1: ffffffff9002cd80 (rtnl_mutex){+.+.}-{4:4}, at: ip_mc_drop_socket+0x80/0x280 net/ipv4/igmp.c:2823
2 locks held by syz.3.4579/23304:
#0: ffffffff9002cd80 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0xa6/0x140 drivers/net/ppp/ppp_generic.c:414
#1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by rm/23322:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 23305 Comm: syz.7.4578 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 1b 49 60 f5 cc
RSP: 0018:ffffc90000007b70 EFLAGS: 00000246
RAX: ffffffff89db4b50 RBX: 0019999999999999 RCX: ffff888032c95d00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0019999999999999
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f70 R12: ffff88807b6782c0
R13: 0019999999999998 R14: 0000000225c17d04 R15: 00000015798ee228
FS: 0000000000000000(0000) GS:ffff888124f54000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f82b37c4a90 CR3: 000000007a8ee000 CR4: 00000000003526f0
Call Trace:
pie_calculate_probability+0x1e0/0x7f0 net/sched/sch_pie.c:345
fq_pie_timer+0x27d/0x5a0 net/sched/sch_fq_pie.c:402
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:folio_batch_add include/linux/folio_batch.h:77 [inline]
RIP: 0010:free_pages_and_swap_cache+0x270/0x490 mm/swap_state.c:585
Code: 44 88 64 24 60 bf 1f 00 00 00 44 89 fe e8 f8 77 9b ff 41 83 ff 1e 0f 87 28 01 00 00 e8 e9 74 9b ff 48 8b 44 24 30 4e 8d 3c f8 <4c> 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 fa 00 09 00
RSP: 0018:ffffc9000681f0a0 EFLAGS: 00000293
RAX: ffffc9000681f108 RBX: 00000000000000e1 RCX: ffff888032c95d00
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000001f
RBP: ffffc9000681f328 R08: ffffea0001253a47 R09: 1ffffd400024a748
R10: dffffc0000000000 R11: fffff9400024a749 R12: 0000000000000009
R13: dffffc0000000000 R14: ffffea0001253a40 R15: ffffc9000681f148
__tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:424
zap_pte_range mm/memory.c:1973 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x4130/0x4f10 mm/memory.c:2109
unmap_vmas+0x390/0x550 mm/memory.c:2178
exit_mmap+0x293/0x9f0 mm/mmap.c:1300
__mmput+0x118/0x420 kernel/fork.c:1187
exit_mm+0x221/0x2d0 kernel/exit.c:615
do_exit+0x6cd/0x2360 kernel/exit.c:997
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
get_signal+0x121b/0x12c0 kernel/signal.c:3046
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 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+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe3759de99
Code: Unable to access opcode bytes at 0x7efe3759de6f.
RSP: 002b:00007efe3850f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007efe37825fa8 RCX: 00007efe3759de99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007efe37825fa8
RBP: 00007efe37825fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe37826038 R14: 00007ffe93bad560 R15: 00007ffe93bad648