INFO: task syz-executor:5852 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:5852 tgid:5852 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: 0033:0x7fb686c1fed7 RSP: 002b:00007ffe85f1f8b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fb686c1fed7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe85f1f970 RBP: 00007ffe85f1f970 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe85f20a00 R13: 00007fb686ca1c05 R14: 0000000000032cd6 R15: 00007ffe85f20a40 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: 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 6 locks held by kworker/0:2/989: 5 locks held by kworker/u8:11/1463: 2 locks held by kworker/u8:13/1499: 3 locks held by kworker/u8:14/1520: #0: ffff88803026b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88803026b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005cdfbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005cdfbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3738 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd3738 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 2 locks held by getty/5603: #0: ffff88823bf328a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5852: #0: ffff88803d4920d0 (&type->s_umount_key#94){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88803d4920d0 (&type->s_umount_key#94){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88803d4920d0 (&type->s_umount_key#94){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 1 lock held by udevd/7675: 10 locks held by syz-executor/8378: 2 locks held by syz.9.435/8630: 3 locks held by syz.8.437/8632: 2 locks held by syz-executor/8634: #0: ffffffff8ecc6840 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8ecd3738 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210 net/ipv4/nexthop.c:3928 2 locks held by syz.7.436/8637: ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1416 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:find_stack lib/stackdepot.c:601 [inline] RIP: 0010:stack_depot_save_flags+0x16c/0x860 lib/stackdepot.c:668 Code: 8b 05 08 51 4b 14 8b 0d fa 50 4b 14 21 e9 48 c1 e1 04 4c 8d 24 08 65 ff 05 b1 67 07 0d 4c 8b 3c 08 4d 39 e7 44 89 2c 24 74 05 <45> 89 d5 eb 34 45 31 ff e9 85 00 00 00 90 0f 0b 90 31 c0 e9 bb 02 RSP: 0018:ffffc9000599f5d8 EFLAGS: 00000287 RAX: ffff88823ae00000 RBX: 0000000000000000 RCX: 00000000000b1810 RDX: 00000000b8408e47 RSI: 0000000000000001 RDI: 0000000048364a76 RBP: 000000006420b181 R08: 000000005c502b54 R09: 00000000f1c5ff6f R10: 000000000000000c R11: ffffffff81aaf310 R12: ffff88823aeb1810 R13: 0000000000000000 R14: ffffc9000599f640 R15: ffff88805d041e60 FS: 0000000000000000(0000) GS:ffff8881268bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69e6a37000 CR3: 000000003e220000 CR4: 00000000003526f0 Call Trace: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x195/0x550 mm/slub.c:4894 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1086 skb_release_all net/core/skbuff.c:1151 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1397 nsim_dev_trap_report drivers/net/netdevsim/dev.c:836 [inline] nsim_dev_trap_report_work+0x7fa/0xbc0 drivers/net/netdevsim/dev.c:866 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