INFO: task syz-executor.3:16842 blocked for more than 143 seconds. Not tainted 6.3.0-syzkaller-13449-g994e2419f1e7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:25064 pid:16842 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 rwsem_down_write_slowpath+0x3e2/0x1220 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1d2/0x200 kernel/locking/rwsem.c:1574 unregister_netdevice_notifier+0x22/0x180 net/core/dev.c:1757 devlink_free+0x2cb/0x460 net/devlink/core.c:269 nsim_drv_remove+0x158/0x1d0 drivers/net/netdevsim/dev.c:1687 device_remove+0xc8/0x170 drivers/base/dd.c:567 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x443/0x610 drivers/base/dd.c:1295 bus_remove_device+0x22c/0x420 drivers/base/bus.c:574 device_del+0x399/0xa30 drivers/base/core.c:3814 device_unregister+0x1e/0xc0 drivers/base/core.c:3844 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline] del_device_store+0x34e/0x4a0 drivers/net/netdevsim/bus.c:219 bus_attr_store+0x76/0xa0 drivers/base/bus.c:170 sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x3f1/0x600 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x945/0xd50 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe94763deef RSP: 002b:00007fe9478cf220 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fe94763deef RDX: 0000000000000001 RSI: 00007fe9478cf270 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 00007fe9478cf1c0 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fe9476e78b6 R13: 00007fe9478cf270 R14: 0000000000000000 R15: 00007fe9478cf940 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c798430 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c798130 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c799040 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6545 2 locks held by getty/4759: #0: ffff88802c08a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 2 locks held by kworker/u4:9/9544: 3 locks held by kworker/1:0/14856: #0: ffff888027e06d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888027e06d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888027e06d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff888027e06d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff888027e06d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff888027e06d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90005507db0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 #2: ffffffff8e114868 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4630 4 locks held by syz-executor.3/16754: 6 locks held by syz-executor.3/16842: #0: ffff88802c218460 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:637 #1: ffff88807a3a9888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x285/0x600 fs/kernfs/file.c:325 #2: ffff888142770a00 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2a9/0x600 fs/kernfs/file.c:326 #3: ffffffff8d7f95e8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xc9/0x4a0 drivers/net/netdevsim/bus.c:209 #4: ffff888045f9c0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #4: ffff888045f9c0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff888045f9c0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffffffff8e100e90 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x22/0x180 net/core/dev.c:1757 1 lock held by syz-executor.3/16888: #0: ffffffff8e100e90 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4cb/0x8e0 net/core/net_namespace.c:487 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.3.0-syzkaller-13449-g994e2419f1e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.3.0-syzkaller-13449-g994e2419f1e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67 Code: 76 53 9e 00 e9 cb fd ff ff e8 6c 53 9e 00 e9 80 fd ff ff e8 62 53 9e 00 e9 4d fd ff ff e8 58 53 9e 00 e9 05 fd ff ff 0f 1f 00 <48> 8b 07 c3 66 66 2e 0f 1f 84 00 00 00 00 00 90 41 57 89 d0 41 56 RSP: 0018:ffffc900001b6d10 EFLAGS: 00000a02 RAX: ffffc900001b8001 RBX: 0000000000000001 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 1ffff92000036dba RDI: ffffc900001b7c70 RBP: ffffc900001b6dd0 R08: ffffffff8f838ffe R09: ffffc900001b7c70 R10: ffffc900001b6d88 R11: 0000000000094001 R12: ffffc900001b6dd8 R13: ffffc900001b6d88 R14: ffffc900001b7c78 R15: ffffc900001b6dbc FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c005e07000 CR3: 0000000026d5e000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:378 [inline] unwind_next_frame+0xaf2/0x1e30 arch/x86/kernel/unwind_orc.c:557 arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:711 [inline] slab_alloc_node mm/slub.c:3451 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x17c/0x3b0 mm/slub.c:3475 skb_ext_maybe_cow net/core/skbuff.c:6710 [inline] skb_ext_add+0xfa/0x790 net/core/skbuff.c:6776 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:160 [inline] br_nf_forward_ip+0xe1/0x13c0 net/bridge/br_netfilter_hooks.c:592 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_slow+0xc9/0x1f0 net/netfilter/core.c:626 nf_hook+0x431/0x730 include/linux/netfilter.h:258 NF_HOOK include/linux/netfilter.h:301 [inline] __br_forward+0x19a/0x570 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0x350/0x450 net/bridge/br_forward.c:189 br_flood+0x168/0x470 net/bridge/br_forward.c:233 br_handle_frame_finish+0xf89/0x1de0 net/bridge/br_input.c:210 br_nf_hook_thresh+0x2fb/0x3f0 net/bridge/br_netfilter_hooks.c:1048 br_nf_pre_routing_finish_ipv6+0x695/0xf30 net/bridge/br_netfilter_ipv6.c:148 NF_HOOK include/linux/netfilter.h:303 [inline] br_nf_pre_routing_ipv6+0x41b/0x830 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0xda4/0x1520 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x9cb/0x1320 net/bridge/br_input.c:416 __netif_receive_skb_core+0xa10/0x3900 net/core/dev.c:5385 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5489 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5605 process_backlog+0x101/0x670 net/core/dev.c:5933 __napi_poll+0xb7/0x6f0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x8a9/0xcb0 net/core/dev.c:6696 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:939 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:931 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308