INFO: task syz-executor.4:7573 blocked for more than 143 seconds. Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:18864 pid:7573 tgid:7573 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x177f/0x49a0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x354/0x620 kernel/sched/completion.c:148 btrfs_qgroup_wait_for_completion+0x92/0xc0 fs/btrfs/qgroup.c:3849 close_ctree+0x118/0xd40 fs/btrfs/disk-io.c:4254 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_anon_super+0x3b/0x70 fs/super.c:1225 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2093 deactivate_locked_super+0xc4/0x130 fs/super.c:472 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267 task_work_run+0x24e/0x310 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:108 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x167/0x360 kernel/entry/common.c:212 do_syscall_64+0x108/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fa09b67f0d7 RSP: 002b:00007ffd43d4c5d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fa09b67f0d7 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffd43d4c690 RBP: 00007ffd43d4c690 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd43d4d750 R13: 00007fa09b6c93b9 R14: 00000000001dd089 R15: 0000000000000007 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4816: #0: ffff88802a3570a0 (&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 1 lock held by syz-executor.4/7573: #0: ffff8880316e00e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880316e00e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880316e00e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:504 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 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:243 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30802 Comm: kworker/u4:32 Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:979 [inline] RIP: 0010:debug_check_no_obj_freed+0x2be/0x580 lib/debugobjects.c:1019 Code: ff c7 48 8b 44 24 38 48 85 c0 0f 84 a4 02 00 00 49 89 c4 49 89 c5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 <74> 08 4c 89 e7 e8 98 33 53 fd 49 8b 04 24 48 89 44 24 38 49 8d 5c RSP: 0018:ffffc900141278c0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8880320a5fa0 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc900141277a0 RBP: ffffc90014127a18 R08: 0000000000000003 R09: fffff52002824ef4 R10: dffffc0000000000 R11: fffff52002824ef4 R12: ffff8880320a5c78 R13: 1ffff11006414b8f R14: ffff888047e40148 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005579b59c7080 CR3: 000000000df32000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: slab_free_hook mm/slub.c:2093 [inline] slab_free mm/slub.c:4299 [inline] kmem_cache_free+0xcc/0x2a0 mm/slub.c:4363 skb_kfree_head net/core/skbuff.c:984 [inline] skb_free_head net/core/skbuff.c:998 [inline] skb_release_data+0x63d/0x850 net/core/skbuff.c:1028 skb_release_all net/core/skbuff.c:1094 [inline] __kfree_skb net/core/skbuff.c:1108 [inline] kfree_skb_reason+0x195/0x390 net/core/skbuff.c:1144 kfree_skb include/linux/skbuff.h:1244 [inline] ieee80211_iface_work+0x270/0xd90 net/mac80211/iface.c:1645 cfg80211_wiphy_work+0x221/0x260 net/wireless/core.c:437 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 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:243