INFO: task syz.1.3175:19172 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3175 state:D stack:28024 pid:19172 tgid:19163 ppid:15149 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
__sys_sendmsg+0x170/0x220 net/socket.c:2678
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe4fdd9af79
RSP: 002b:00007fe4fec54028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe4fe016180 RCX: 00007fe4fdd9af79
RDX: 00000000200048d0 RSI: 0000200000000200 RDI: 000000000000000a
RBP: 00007fe4fde316e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe4fe016218 R14: 00007fe4fe016180 R15: 00007ffc12ab7828
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5e31a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:302 [inline]
#0: ffffffff8e5e31a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e5e31a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/0:2/796:
#0: ffff8880b843ae18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#0: ffff8880b843ae18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
#1: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffff8880b8424608 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2b71/0x5fa0 kernel/sched/core.c:6861
2 locks held by syz-executor/9584:
#0: ffff88803d1e80e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88803d1e80e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88803d1e80e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88803d1e80e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ea47ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz-executor/15472:
#0: ffff88814132a0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88814132a0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88814132a0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88814132a0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ea47ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by syz.1.3175/19168:
#0: ffffffff904adad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea47ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
2 locks held by syz.1.3175/19172:
#0: ffffffff904adad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea47ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1886
2 locks held by getty/19215:
#0: ffff888031d740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90004cbb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
2 locks held by syz.7.3367/20167:
#0: ffffffff904adad0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea47ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xc4/0x7a0 fs/nfsd/nfsctl.c:1736
5 locks held by kworker/u11:11/21511:
5 locks held by kworker/u11:20/21523:
#0: ffff88801c2e7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90003e9fc98 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903e8330 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xab/0x830 net/core/net_namespace.c:670
#3: ffffffff90400c68 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff90400c68 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
#4: ffffffff8e5eedb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.5.3643/21590:
#0: ffff888031c8c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888031c8c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888031c8c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff888031c8c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ea47ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
1 lock held by syz.5.3643/21591:
#0: ffff888031c8c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888031c8c0e0 (&type->s_umount_key#54){+.+.}-{4:4}, at: super_lock+0x1ca/0x3f0 fs/super.c:122
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 21510 Comm: kworker/u11:10 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1091 [inline]
RIP: 0010:debug_check_no_obj_freed+0x210/0x630 lib/debugobjects.c:1129
Code: 00 00 48 89 c2 31 f6 49 89 df 4c 89 74 24 28 48 c1 ea 03 89 f3 42 80 3c 22 00 0f 85 dd 00 00 00 48 8d 78 18 83 c3 01 4c 8b 30 <48> 89 fa 48 c1 ea 03 42 80 3c 22 00 0f 85 27 03 00 00 48 8b 50 18
RSP: 0018:ffffc900046678b0 EFLAGS: 00000002
RAX: ffff88803334c460 RBX: 0000000000000002 RCX: ffffffff81e307c8
RDX: 1ffff1100666988c RSI: 0000000000000000 RDI: ffff88803334c478
RBP: ffffc900046679e0 R08: 0000000000000001 R09: fffff520008ccf04
R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888068498000 R14: 0000000000000000 R15: ffff888068499000
FS: 0000000000000000(0000) GS:ffff8881245c4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f805ff8 CR3: 0000000078e52000 CR4: 00000000003526f0
Call Trace:
slab_free_hook mm/slub.c:2471 [inline]
slab_free mm/slub.c:6674 [inline]
kfree+0x34c/0x690 mm/slub.c:6886
skb_kfree_head net/core/skbuff.c:1068 [inline]
skb_free_head+0x119/0x220 net/core/skbuff.c:1080
skb_release_data+0x540/0x700 net/core/skbuff.c:1107
skb_release_all net/core/skbuff.c:1182 [inline]
__kfree_skb net/core/skbuff.c:1196 [inline]
consume_skb net/core/skbuff.c:1429 [inline]
consume_skb+0xc4/0x110 net/core/skbuff.c:1423
nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline]
nsim_dev_trap_report_work+0x8cf/0xd10 drivers/net/netdevsim/dev.c:921
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246