INFO: task syz.4.2395:17242 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2395 state:D stack:27280 pid:17242 tgid:17233 ppid:5868 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
sync_bdevs+0x1ac/0x340 block/bdev.c:1288
ksys_sync+0xb9/0x150 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f53ff38ebe9
RSP: 002b:00007f5400200038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f53ff5b6270 RCX: 00007f53ff38ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f53ff5b6270 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f53ff5b6308 R14: 00007f53ff5b6270 R15: 00007ffedc9b4aa8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:7/3529:
2 locks held by getty/5617:
#0: ffff88802f9f70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5879:
#0: ffff8881433c4358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
3 locks held by kworker/u8:24/11312:
#0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90004897bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90004897bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by kworker/u8:6/15778:
#0: ffff88802f2fc148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88802f2fc148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000dd2fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000dd2fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
5 locks held by kworker/u8:8/16539:
#0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90003f6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003f6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f52b5b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
#3: ffff88804fa154e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x2f0 drivers/net/wireguard/device.c:249
#4: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#4: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz.4.2395/17242:
#0: ffff8881433c4358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ac/0x340 block/bdev.c:1288
7 locks held by syz-executor/18051:
#0: ffff88807514c428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff88807514c428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
#1: ffff888030553c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325
#2: ffff888026871d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8edaf368 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff88807e3f30e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88807e3f30e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff88807e3f30e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffff88801cbe8250 (&devlink->lock_key#17){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
#6: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142
4 locks held by syz-executor/18057:
#0: ffff888074868dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff888074868dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2715
#1: ffff8880748680b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282
#2: ffffffff8f69d108 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline]
#2: ffffffff8f69d108 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2575
#3: ffff88807b575b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762
3 locks held by syz-executor/18178:
#0: ffffffff8eca86c0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8eca86c0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8eca86c0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
#2: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz-executor/18422:
#0: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
2 locks held by syz.3.2659/18429:
#0: ffff88802913c6d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2406
#1: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f538448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6814
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 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: 17414 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:do_raw_spin_unlock+0xb/0x240 kernel/locking/spinlock_debug.c:139
Code: ff ff ff e8 77 15 85 00 e9 60 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 41 57 41 56 41 55 <41> 54 53 48 89 fb 49 bc 00 00 00 00 00 fc ff df 4c 8d 77 04 4c 89
RSP: 0018:ffffc9000b12fac0 EFLAGS: 00000282
RAX: 4a4819a2d958f200 RBX: ffff8880b873fd00 RCX: 4a4819a2d958f200
RDX: 0000000000000000 RSI: ffffffff8dba6738 RDI: ffff8880b873fd00
RBP: 0000000000000000 R08: ffff8880b873fd00 R09: 000000000000003f
R10: 00000000000014e7 R11: ffffed1027fff830 R12: ffffffff8dbded18
R13: ffff8880b873fd00 R14: ffff88813fffbb80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000020000 CR3: 000000005d91a000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
__free_frozen_pages+0x687/0xd30 mm/page_alloc.c:2924
vfree+0x25a/0x400 mm/vmalloc.c:3434
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:535
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:961
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3be078ebe9
Code: Unable to access opcode bytes at 0x7f3be078ebbf.
RSP: 002b:00007ffdfb7a2858 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f3be0813653 RCX: 00007f3be078ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f3be0813665 R08: 00007ffdfb7a05f7 R09: 00000000000927c0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00000000000927c0 R14: 00000000001876b6 R15: 00007ffdfb7a2a00