INFO: task syz-executor.0:26432 blocked for more than 143 seconds. Not tainted 6.8.0-rc4-syzkaller-01049-g1e63e5a813fa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20984 pid:26432 tgid:26432 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17d1/0x49f0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6874 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a3/0xd70 kernel/locking/mutex.c:752 del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2085 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa81/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f6ff6a7caef RSP: 002b:00007fff15037ac0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f6ff6a7caef RDX: 0000000000000001 RSI: 00007fff15037b10 RDI: 0000000000000005 RBP: 00007f6ff6aca021 R08: 0000000000000000 R09: 00007fff15037917 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007fff15037b10 R14: 00007f6ff76d4620 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 1 lock held by dhcpcd/4734: #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xde/0xc80 net/netlink/af_netlink.c:2211 2 locks held by getty/4822: #0: ffff88802b39b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by kworker/u4:11/3520: #0: ffff88802b251538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff88802b251538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000a2cfd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000a2cfd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4179 2 locks held by kworker/u4:2/24368: 6 locks held by kworker/u4:5/24370: #0: ffff8880162f4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff8880162f4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9001553fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9001553fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffffffff8f36a650 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:591 #3: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: wiphy_unregister+0x236/0xa80 net/wireless/core.c:1096 #4: ffff8880121f8768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:5932 [inline] #4: ffff8880121f8768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_unregister+0x240/0xa80 net/wireless/core.c:1097 #5: ffffffff8e136478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #5: ffffffff8e136478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x46c/0x890 kernel/rcu/tree_exp.h:995 7 locks held by syz-executor.2/26273: #0: ffff88801e1fc420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2792 [inline] #0: ffff88801e1fc420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 #1: ffff88804122c088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888022a81ba8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8ecb6728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff888043afa0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:990 [inline] #4: ffff888043afa0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff888043afa0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1292 #5: ffff888043afb250 (&devlink->lock_key#4){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8e136478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #6: ffffffff8e136478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:995 3 locks held by kworker/0:62/26408: #0: ffff888014c8c938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c8c938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90003717d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90003717d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 2 locks held by kworker/0:64/26410: #0: ffff888014c8e538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888014c8e538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90003737d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90003737d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 4 locks held by syz-executor.0/26432: #0: ffff88801e1fc420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2792 [inline] #0: ffff88801e1fc420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 #1: ffff888041ec6088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 #2: ffff888022a81ba8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 #3: ffffffff8ecb6728 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 1 lock held by syz-executor.3/26725: 1 lock held by syz-executor.4/26732: #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6594 1 lock held by syz-executor.2/26735: #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6594 1 lock held by syz-executor.0/26740: #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6594 1 lock held by syz-executor.1/26773: #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f376bc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6594 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc4-syzkaller-01049-g1e63e5a813fa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 26725 Comm: syz-executor.3 Not tainted 6.8.0-rc4-syzkaller-01049-g1e63e5a813fa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:__lock_acquire+0x126c/0x1fd0 kernel/locking/lockdep.c:5134 Code: 10 8b 18 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 20 54 c9 92 be 08 00 00 00 e8 dc b7 84 00 48 0f a3 1d a4 25 58 11 <73> 1d 48 69 c3 c8 00 00 00 48 8d 98 20 b3 97 92 48 ba 00 00 00 00 RSP: 0018:ffffc90004bb7810 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000021 RCX: ffffffff81712e74 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff92c95420 RBP: 68ddc444da0a8dc5 R08: ffffffff92c95427 R09: 1ffffffff2592a84 R10: dffffc0000000000 R11: fffffbfff2592a85 R12: ffff88802295d940 R13: ffff88802295d940 R14: 0000000000000000 R15: ffff88802295d940 FS: 0000555556b81480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f44950d5000 CR3: 0000000098bce000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] inet_twsk_purge+0x168/0xb80 net/ipv4/inet_timewait_sock.c:277 ops_exit_list net/core/net_namespace.c:175 [inline] setup_net+0xa3b/0xca0 net/core/net_namespace.c:372 copy_net_ns+0x4e3/0x7b0 net/core/net_namespace.c:505 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x122/0x180 kernel/nsproxy.c:228 ksys_unshare+0x616/0xc00 kernel/fork.c:3428 __do_sys_unshare kernel/fork.c:3499 [inline] __se_sys_unshare kernel/fork.c:3497 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3497 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fc6c207f507 Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe988c8a88 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fc6c207f507 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007ffe988c8b60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe988c9148 R13: 0000000000000003 R14: 00007fc6c21ac9d8 R15: 000000000000000c