INFO: task syz.0.522:8676 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.522 state:D stack:25512 pid:8676 tgid:8675 ppid:5864 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+0xa98/0xc70 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/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb4be18eba9
RSP: 002b:00007fb4bef9d038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb4be3d5fa0 RCX: 00007fb4be18eba9
RDX: 0000000000004000 RSI: 0000200000000480 RDI: 0000000000000003
RBP: 00007fb4be211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb4be3d6038 R14: 00007fb4be3d5fa0 R15: 00007ffd4a6166e8
Showing all locks held in the system:
3 locks held by kworker/1:0/24:
#0: ffff88801b880d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc900001e7d10 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffffffff8e5cc880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3815
1 lock held by khungtaskd/31:
#0: ffffffff8e5c1420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c1420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c1420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5869:
#0: ffff8880537740e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880537740e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880537740e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff8880537740e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9d9c88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
2 locks held by getty/8043:
#0: ffff88803176c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032802f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by kworker/u8:17/8427:
#0: ffff88801f7c9148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc90002ee7d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
2 locks held by syz.2.507/8619:
#0: ffffffff9042bd10 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9d9c88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b10 fs/nfsd/nfsctl.c:1919
2 locks held by syz.0.522/8676:
#0: ffffffff9042bd10 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e9d9c88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x687/0xbc0 fs/nfsd/nfsctl.c:1629
2 locks held by kworker/u8:24/8784:
#0: ffff88801f7c9148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc9000b9c7d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
4 locks held by kworker/u8:28/8788:
#0: ffff88801c6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211
#1: ffffc9000b7e7d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212
#2: ffffffff90372550 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658
#3: ffffffff90388848 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:172 [inline]
#3: ffffffff90388848 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:247
3 locks held by syz.1.571/8882:
#0: ffffffff9042bd10 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffff888031c826d8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2406
#2: ffffffff8e9d9c88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xb6/0x1170 fs/nfsd/nfsctl.c:1516
2 locks held by syz-executor/8919:
#0: ffff88803261e0e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803261e0e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803261e0e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
#0: ffff88803261e0e0 (&type->s_umount_key#59){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503
#1: ffffffff8e9d9c88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
1 lock held by syz-executor/10527:
#0: ffffffff8e5cc9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.6.972/10852:
#0: ffffffff8e5cc9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz.4.977/10886:
#0: ffffffff90372550 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:566
#1: ffffffff8e5cc880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3815
=============================================
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 08/18/2025
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+0x56d/0x730 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: 48 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events drain_vmap_area_work
RIP: 0010:__orc_find+0x56/0xf0 arch/x86/kernel/unwind_orc.c:100
Code: b9 00 00 00 00 00 fc ff df 49 89 ff 48 89 fd eb 0c 48 8d 6b 04 49 89 df 49 39 ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f <48> c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 48 89 da 48 c1 ea 03
RSP: 0018:ffffc90000b87538 EFLAGS: 00000246
RAX: ffffffff914e2700 RBX: ffffffff90c57c84 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff90c57c80
RBP: ffffffff90c57c80 R08: ffffffff914e2736 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000010ee2 R12: ffffffff90c57c80
R13: ffffffff820ee27d R14: ffffffff90c57c80 R15: ffffffff90c57c80
FS: 0000000000000000(0000) GS:ffff8881247ba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c60ebf7000 CR3: 0000000034a0e000 CR4: 00000000003526f0
Call Trace:
orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
unwind_next_frame+0x2ec/0x20a0 arch/x86/kernel/unwind_orc.c:494
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2422 [inline]
slab_free mm/slub.c:4695 [inline]
kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4797
__merge_or_add_vmap_area mm/vmalloc.c:1459 [inline]
merge_or_add_vmap_area_augment mm/vmalloc.c:1516 [inline]
reclaim_list_global.part.0+0x7d2/0x1a70 mm/vmalloc.c:2180
reclaim_list_global mm/vmalloc.c:2175 [inline]
decay_va_pool_node+0xcce/0x1080 mm/vmalloc.c:2235
__purge_vmap_area_lazy+0x139/0xc60 mm/vmalloc.c:2315
drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2390
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245