INFO: task syz.2.523:7376 blocked for more than 163 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.523 state:D stack:25448 pid:7376 ppid:6852 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 iterate_supers+0xa4/0x1d0 fs/super.c:755 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:937 [inline] __se_sys_quotactl+0x33a/0x6b0 fs/quota/quota.c:916 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1ef178f749 RSP: 002b:00007f1ef2659038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f1ef19e5fa0 RCX: 00007f1ef178f749 RDX: 0000000000000022 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f1ef1813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ef19e6038 R14: 00007f1ef19e5fa0 R15: 00007ffde87a63b8 INFO: task syz.9.599:7804 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.599 state:D stack:27648 pid:7804 ppid:6814 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 iterate_supers+0xa4/0x1d0 fs/super.c:755 ksys_sync+0x91/0x150 fs/sync.c:102 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8475f8f749 RSP: 002b:00007f8476ebc038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f84761e6090 RCX: 00007f8475f8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f84761e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f84761e6128 R14: 00007f84761e6090 R15: 00007fffe53cb5b8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by kworker/1:6/4336: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004417d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 2 locks held by kworker/1:9/4579: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900056a7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 1 lock held by syz.0.183/5292: 3 locks held by syz-executor/6820: #0: ffff8880235cd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff8880235cd0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff8880235cc078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline] #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 1 lock held by syz.2.523/7376: #0: ffff8880761200e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.9.599/7804: #0: ffff8880761200e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.0.677/8259: #0: ffff8880761200e0 (&type->s_umount_key#32){++++}-{3:3}, at: user_get_super+0x118/0x240 fs/super.c:889 1 lock held by syz.3.715/8488: #0: ffff8880761200e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.7.922/9566: #0: ffff8880761200e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 1 lock held by syz.4.941/9664: #0: ffff8880761200e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 3 locks held by syz-executor/9679: #0: ffff88803c8b90b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88803c8b90b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff88803c8b8078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline] #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 3 locks held by syz-executor/9836: #0: ffff888081af10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888081af10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff888081af0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline] #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 3 locks held by syz.6.978/9895: #0: ffff88805cdf10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88805cdf10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff88805cdf0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233 #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 3 locks held by kworker/u4:27/9915: 3 locks held by syz.8.984/9928: #0: ffff888041cd10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888041cd10b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1fa/0x4f0 net/bluetooth/hci_core.c:2705 #1: ffff888041cd0078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x458/0xf40 net/bluetooth/hci_sync.c:5233 #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1826 [inline] #2: ffffffff8dc98f48 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xac/0x290 net/bluetooth/hci_conn.c:2504 1 lock held by dhcpcd/9944: #0: ffff888041f82130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1792 [inline] #0: ffff888041f82130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3248 2 locks held by sed/9950: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 128 Comm: kworker/0:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events free_obj_work RIP: 0010:unwind_next_frame+0x66f/0x20b0 arch/x86/kernel/unwind_orc.c:475 Code: 85 e3 15 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 ef 15 00 00 49 0f bf 04 24 48 01 c5 e9 fa 00 00 00 4c 8d 7b 40 <4c> 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 eb a5 98 00 RSP: 0018:ffffc90002dd75f0 EFLAGS: 00000293 RAX: 0000000000000014 RBX: ffffc90002dd76c8 RCX: ffffffff8e2ed978 RDX: ffffffff8eae60f8 RSI: ffffffff8e2ed974 RDI: ffffffff8138655f RBP: ffffffff8eae60fc R08: 0000000000000001 R09: 0000000000000005 R10: fffff520005baee5 R11: 1ffff920005baee3 R12: ffffffff8eae60f8 R13: dffffc0000000000 R14: ffffffff8e2ed974 R15: ffffc90002dd7708 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c0a9b46950 CR3: 000000007dc23000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0xf7/0x290 mm/slub.c:3709 free_obj_work+0x410/0x580 lib/debugobjects.c:332 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295