INFO: task syz.7.2852:16365 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.2852 state:D stack:27160 pid:16365 tgid:16363 ppid:14989 task_flags:0x400140 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f703679e0d9 RSP: 002b:00007f70375a9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7036a25fa0 RCX: 00007f703679e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f7036835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7036a26038 R14: 00007f7036a25fa0 R15: 00007ffd8125d718 INFO: task syz.6.2872:16440 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.2872 state:D stack:28776 pid:16440 tgid:16439 ppid:11959 task_flags:0x400140 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbddf59e0d9 RSP: 002b:00007fbde040a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbddf825fa0 RCX: 00007fbddf59e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fbddf635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbddf826038 R14: 00007fbddf825fa0 R15: 00007ffc2daedd88 INFO: task syz.0.2878:16458 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2878 state:D stack:28776 pid:16458 tgid:16457 ppid:5597 task_flags:0x400140 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 write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 nfsctl_transaction_write+0x106/0x1a0 fs/nfsd/nfsctl.c:112 vfs_write+0x2aa/0x1050 fs/read_write.c:685 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f87b299e0d9 RSP: 002b:00007f87b38b9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f87b2c25fa0 RCX: 00007f87b299e0d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f87b2a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87b2c26038 R14: 00007f87b2c25fa0 R15: 00007ffe06b399f8 INFO: task syz.0.2878:16460 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2878 state:D stack:28856 pid:16460 tgid:16457 ppid:5597 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 fdget_pos+0x2aa/0x380 fs/file.c:1259 class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_write+0x71/0x250 fs/read_write.c:730 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f87b299e0d9 RSP: 002b:00007f87b3898028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f87b2c26090 RCX: 00007f87b299e0d9 RDX: 00000000000000e1 RSI: 0000200000000300 RDI: 0000000000000003 RBP: 00007f87b2a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87b2c26128 R14: 00007f87b2c26090 R15: 00007ffe06b399f8 Showing all locks held in the system: 1 lock held by ksoftirqd/0/15: #0: ffff8880b843b520 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:675 [inline] #0: ffff8880b843b520 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:659 1 lock held by khungtaskd/31: #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ebe8200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5353: #0: ffff888037b8e0a0 (&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 3 locks held by syz.3.2483/14855: #0: ffff888076787270 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff88807ed0e450 (sb_writers#20){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: write_threads+0x278/0x570 fs/nfsd/nfsctl.c:432 3 locks held by syz.7.2852/16365: #0: ffff8880310c6470 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff8880332de450 (sb_writers#20){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 3 locks held by syz.6.2872/16440: #0: ffff888027bc7430 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff888031ff2450 (sb_writers#20){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 3 locks held by syz.0.2878/16458: #0: ffff88802c59f0b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff88804c9e4450 (sb_writers#20){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffffffff8f0724c0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xa5/0xcc0 fs/nfsd/nfsctl.c:860 1 lock held by syz.0.2878/16460: #0: ffff88802c59f0b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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: 57 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data+0x18/0x90 kernel/kcov.c:246 Code: 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 f9 d3 58 12 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d d0 d3 58 12 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 e9 00 98 RSP: 0018:ffffc900015e78c8 EFLAGS: 00000246 RAX: 0000000080000000 RBX: ffff88806b30c6d0 RCX: ffffffff8b2dbc9c RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801bdb8000 RBP: ffffc900015e7a80 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888023be7000 R12: 0000000000000000 R13: ffff8880793acec0 R14: 0000000000000000 R15: ffff888023be7000 FS: 0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fefde1f14b8 CR3: 000000000e994000 CR4: 00000000003526f0 Call Trace: ieee80211_update_sta_info.isra.0+0x1dc/0x1230 net/mac80211/ibss.c:940 ieee80211_rx_bss_info net/mac80211/ibss.c:1061 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1544 [inline] ieee80211_ibss_rx_queued_mgmt+0xdea/0x1c70 net/mac80211/ibss.c:1571 ieee80211_iface_process_skb net/mac80211/iface.c:1769 [inline] ieee80211_iface_work+0xa9a/0x1070 net/mac80211/iface.c:1823 cfg80211_wiphy_work+0x2b7/0x550 net/wireless/core.c:538 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 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