INFO: task syz.3.1207:10448 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1207 state:D stack:25728 pid:10448 ppid:4270 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 iterate_supers+0xa4/0x1d0 fs/super.c:755 ksys_sync+0x91/0x150 fs/sync.c:102 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9b7938f749 RSP: 002b:00007f9b7a236038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f9b795e5fa0 RCX: 00007f9b7938f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f9b795e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b795e6038 R14: 00007f9b795e5fa0 R15: 00007fff3313a938 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 5 locks held by kworker/u4:2/40: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b17d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11489 #4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 3 locks held by kworker/1:1/41: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b27d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104 1 lock held by dhcpcd/3931: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 2 locks held by getty/4027: #0: ffff88803000b098 (&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+0x41b/0x1380 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/4265: #0: ffff888023f020e0 (&type->s_umount_key#67){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 3 locks held by kworker/0:4/4322: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900046c7d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 2 locks held by kworker/1:6/4332: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004767d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/u4:31/10055: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003e5fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 1 lock held by syz.3.1207/10448: #0: ffff888023f020e0 (&type->s_umount_key#67){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.0.1284/10923: #0: ffff888023f020e0 (&type->s_umount_key#67){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 7 locks held by syz-executor/11957: #0: ffff88807df66460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff8880425c2c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff888144f08578 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888144f08578 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d44d168 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209 #4: ffff8880587980e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #4: ffff8880587980e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline] #4: ffff8880587980e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283 #5: ffff8880550a32f8 (&devlink->lock_key#16){+.+.}-{3:3}, at: nsim_drv_remove+0x54/0x160 drivers/net/netdevsim/dev.c:1677 #6: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: unregister_netdevice_notifier_net+0x8a/0x280 net/core/dev.c:1928 1 lock held by syz.5.1533/12215: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 1 lock held by syz.8.1537/12243: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 1 lock held by syz.8.1537/12244: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 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+0xeee/0xf30 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: 11 Comm: kworker/u4:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: phy31 ieee80211_iface_work RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0x66/0xe0 kernel/kcov.c:349 Code: 1a 70 8a 48 8b 54 24 20 65 4c 8b 05 c4 8a 81 7e 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d b2 8a 81 7e <41> 81 e3 00 01 ff 00 74 13 41 81 fb 00 01 00 00 75 d9 41 83 b8 1c RSP: 0018:ffffc90000107118 EFLAGS: 00000216 RAX: 0000000000000028 RBX: dffffc0000000000 RCX: 0000000000000001 RDX: ffffffff8997cab5 RSI: ffffffff8dda3360 RDI: 0000000000000006 RBP: ffffc900001074d0 R08: ffff88813fe83b80 R09: 000000000000000a R10: 0000000000000025 R11: 0000000080000000 R12: ffff8880564e409c R13: 0000000000000004 R14: ffff8880564e4089 R15: 0000000000000006 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c42093a CR3: 000000000c68e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _ieee802_11_parse_elems_full+0x685/0x30c0 net/mac80211/util.c:1051 ieee802_11_parse_elems_full+0xcf6/0x1230 net/mac80211/util.c:1522 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2246 [inline] ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2253 [inline] ieee80211_bss_info_update+0x7ed/0xbc0 net/mac80211/scan.c:212 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+0x17b4/0x2b10 net/mac80211/ibss.c:1638 ieee80211_iface_process_skb net/mac80211/iface.c:1679 [inline] ieee80211_iface_work+0x726/0xc80 net/mac80211/iface.c:1733 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295