INFO: task syz.1.542:7296 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.542 state:D stack:26576 pid:7296 ppid:5017 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747 write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114 vfs_write+0x2dc/0x9a0 fs/read_write.c:582 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc53679de99 RSP: 002b:00007fc537590028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc536a25fa0 RCX: 00007fc53679de99 RDX: 0000000000000009 RSI: 0000200000000240 RDI: 0000000000000004 RBP: 00007fc536833eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc536a26038 R14: 00007fc536a25fa0 R15: 00007ffd51a5f138 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527 2 locks held by getty/4030: #0: ffff88802ff93098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 2 locks held by syz.2.38/4525: #0: ffff88807a01a0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4f/0x1a0 fs/nfsd/nfssvc.c:633 2 locks held by syz.5.396/6598: #0: ffff8880606800e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4f/0x1a0 fs/nfsd/nfssvc.c:633 3 locks held by syz.3.495/7076: #0: ffff888068a1d4e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88801c678460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by syz.1.542/7296: #0: ffff88804dbc9768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff8880771c0460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846 3 locks held by kworker/u4:18/9638: 3 locks held by syz.7.1246/10259: 1 lock held by syz.8.1247/10263: #0: ffff88802fc517d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88802fc517d8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x16c/0x2d0 mm/util.c:518 2 locks held by syz.8.1247/10264: 1 lock held by syz.8.1247/10265: 5 locks held by syz.7.1248/10269: 2 locks held by sed/10268: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4328 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:hlock_class kernel/locking/lockdep.c:223 [inline] RIP: 0010:mark_lock+0x56/0x320 kernel/locking/lockdep.c:4611 Code: 03 42 0f b6 04 28 84 c0 0f 85 74 02 00 00 41 0f b6 47 02 24 03 3c 01 bd 09 00 00 00 83 dd 00 41 bc 01 00 00 00 89 e9 41 d3 e4 <4d> 8d 7e 20 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 22 02 RSP: 0018:ffffc90004256f20 EFLAGS: 00000002 RAX: 0000000000040603 RBX: ffff88802659da00 RCX: 0000000000000002 RDX: 0000000000000002 RSI: ffff88802659e580 RDI: ffff88802659da00 RBP: 0000000000000002 R08: dffffc0000000000 R09: 1ffffffff2161e55 R10: dffffc0000000000 R11: fffffbfff2161e56 R12: 0000000000000004 R13: dffffc0000000000 R14: ffff88802659e580 R15: ffff88802659e5a0 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002020 CR3: 00000000480d0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4542 [inline] __lock_acquire+0xd88/0x7c40 kernel/locking/lockdep.c:5017 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] cfg80211_bss_update+0x80/0x21a0 net/wireless/scan.c:1837 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2509 [inline] cfg80211_inform_bss_frame_data+0xa77/0x1390 net/wireless/scan.c:2542 ieee80211_bss_info_update+0x6ef/0xbf0 net/mac80211/scan.c:190 ieee80211_rx_bss_info net/mac80211/ibss.c:1120 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1609 [inline] ieee80211_ibss_rx_queued_mgmt+0x1931/0x2eb0 net/mac80211/ibss.c:1638 ieee80211_iface_process_skb net/mac80211/iface.c:1679 [inline] ieee80211_iface_work+0x72c/0xc70 net/mac80211/iface.c:1733 cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295