INFO: task syz-executor:5845 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21608 pid:5845 tgid:5845 ppid:1 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 __bch2_fs_stop+0x704/0x900 fs/bcachefs/super.c:696 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb2127801f7 RSP: 002b:00007ffd8b7f7568 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fb2127801f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd8b7f7620 RBP: 00007ffd8b7f7620 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffd8b7f86b0 R13: 00007fb212801d7d R14: 000000000002d9df R15: 00007ffd8b7f86f0 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/43: #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a6f4138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90000b47bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000b47bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecc6a20 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:172 [inline] #3: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:247 3 locks held by kworker/0:2/1230: #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900052cfbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900052cfbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:8/1390: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900057dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900057dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 7 locks held by kworker/u8:10/1417: 2 locks held by kworker/u8:12/1458: 2 locks held by dhcpcd/5502: #0: ffffffff8ed39940 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17364 2 locks held by getty/5603: #0: ffff88823bf348a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5845: #0: ffff8880335620d0 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880335620d0 (&type->s_umount_key#59){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880335620d0 (&type->s_umount_key#59){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 3 locks held by kworker/u8:16/7524: #0: ffff88814cd5c938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88814cd5c938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc900040d7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900040d7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 1 lock held by syz-executor/7866: #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 1 lock held by syz-executor/7905: #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/7911: #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 7 locks held by syz-executor/7947: #0: ffff8880349b2488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3108 [inline] #0: ffff8880349b2488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff888029284078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff888027486e18 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888027486e18 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e542fb8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff888054f470d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888054f470d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffff888035dce300 (&devlink->lock_key#19){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582 #6: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 1 lock held by syz-executor/7966: #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd3938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 1458 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 1b 3c 5a 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90005aaf948 EFLAGS: 00000206 RAX: dd90b605ab79d600 RBX: 0000000000000000 RCX: dd90b605ab79d600 RDX: 0000000000000000 RSI: ffffffff8d21af85 RDI: ffffffff8b621680 RBP: ffffffff8ac48dea R08: 0000000000000000 R09: ffffffff8ac48dea R10: dffffc0000000000 R11: ffffffff8ac48cd0 R12: 0000000000000002 R13: ffffffff8d9a8d80 R14: 0000000000000000 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f456527a6b0 CR3: 000000000d7a6000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x13b/0xbc0 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245