INFO: task syz.3.1958:11696 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1958 state:D stack:27880 pid:11696 ppid:5780 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6a9/0xcc0 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
bdev_open_by_dev+0x77/0x100 block/bdev.c:859
setup_bdev_super+0x59/0x660 fs/super.c:1496
mount_bdev+0x1d3/0x2d0 fs/super.c:1640
legacy_get_tree+0xea/0x180 fs/fs_context.c:662
vfs_get_tree+0x8c/0x280 fs/super.c:1764
do_new_mount+0x24b/0xa40 fs/namespace.c:3386
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f66bad9cdd9
RSP: 002b:00007f66bbbb7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f66bb016270 RCX: 00007f66bad9cdd9
RDX: 0000200000000000 RSI: 0000200000000100 RDI: 0000200000000040
RBP: 00007f66bae32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000001000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f66bb016308 R14: 00007f66bb016270 R15: 00007ffe87e60b58
Showing all locks held in the system:
1 lock held by rcu_preempt/17:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
1 lock held by khungtaskd/29:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:2/35:
#0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88801a254938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc90000abfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc90000abfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffffffff8e3b5a90 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x14c/0xbb0 net/core/net_namespace.c:606
#3: ffffffff8d137980 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089
3 locks held by kworker/1:2/968:
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc900049e7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900049e7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by getty/5526:
#0: ffff888031d020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by udevd/10897:
#0: ffff8880228cd4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
1 lock held by syz.3.1958/11696:
#0: ffff8880228cd4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805
4 locks held by syz-executor/12634:
#0: ffff8880306f0e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff8880306f0e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x500 net/bluetooth/hci_core.c:2709
#1: ffff8880306f00b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x5d6/0x1220 net/bluetooth/hci_sync.c:5288
#2: ffffffff8e5307a8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
#2: ffffffff8e5307a8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2541
#3: ffff88807e223b38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1759
2 locks held by syz.1.2588/13707:
#0: ffffffff8e3b5a90 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516
#1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 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+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13710 Comm: syz.4.2589 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:980 [inline]
RIP: 0010:debug_check_no_obj_freed+0x170/0x540 lib/debugobjects.c:1020
Code: 48 ba 00 00 00 00 00 fc ff df 48 89 44 24 38 80 3c 10 00 74 12 48 89 df e8 cd 08 ae fd 48 ba 00 00 00 00 00 fc ff df 48 8b 2b <48> 85 ed 0f 84 95 03 00 00 48 89 5c 24 30 4c 89 74 24 28 4c 89 7c
RSP: 0018:ffffc90003df7808 EFLAGS: 00000046
RAX: 1ffffffff2e92527 RBX: ffffffff97492938 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90003df76e0
RBP: ffff88806014be00 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520007beedc R12: ffffc9001a72d000
R13: ffffc9001a32d000 R14: ffffc9001a5bb000 R15: 0000000000000172
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000001a000 CR3: 000000000cf32000 CR4: 00000000003526e0
Call Trace:
remove_vm_area+0x1d3/0x2f0 mm/vmalloc.c:2726
vfree+0x63/0x320 mm/vmalloc.c:2849
kcov_put kernel/kcov.c:438 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:534
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1d4/0x260 kernel/task_work.c:245
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x95a/0x2460 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x13f0 kernel/signal.c:2902
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f398d59cdd9
Code: Unable to access opcode bytes at 0x7f398d59cdaf.
RSP: 002b:00007f398e37f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000004 RBX: 00007f398d815fa0 RCX: 00007f398d59cdd9
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003
RBP: 00007f398d632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f398d816038 R14: 00007f398d815fa0 R15: 00007ffd86ad4568