INFO: task syz.8.644:8703 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.644 state:D stack:26560 pid:8703 tgid:8702 ppid:6786 task_flags:0x480140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
relay_open+0x3b8/0x920 kernel/relay.c:515
blk_trace_setup_prepare+0x425/0x5a0 kernel/trace/blktrace.c:716
blk_trace_setup+0x2f8/0x520 kernel/trace/blktrace.c:790
blk_trace_ioctl+0x37f/0x920 kernel/trace/blktrace.c:938
blkdev_ioctl+0x4c1/0x740 block/ioctl.c:793
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb35d9c629
RSP: 002b:00007fbb33ff6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbb36015fa0 RCX: 00007fbb35d9c629
RDX: 0000200000000240 RSI: 00000000c0481273 RDI: 0000000000000007
RBP: 00007fbb35e32b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbb36016038 R14: 00007fbb36015fa0 R15: 00007fff6b461f08
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
#0: ffff88813fe44148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe44148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8fbcc688 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5573:
#0: ffff888036ac00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by syz.3.157/6570:
3 locks held by kworker/u8:18/7531:
#0: ffff88803192a948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88803192a948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000cebfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000cebfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8fbcc688 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8fbcc688 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4198
2 locks held by syz.8.644/8703:
#0: ffff888025de9268 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline]
#0: ffff888025de9268 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline]
#0: ffff888025de9268 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:789
#1: ffffffff8e7bdf48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:515
2 locks held by syz.1.739/9355:
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline]
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock block/blk.h:752 [inline]
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x2d3/0x520 kernel/trace/blktrace.c:789
#1: ffffffff8e7bdf48 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:515
1 lock held by syz.1.739/9356:
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline]
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:904
1 lock held by syz.1.739/9357:
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_debugfs_lock_nomemsave block/blk.h:740 [inline]
#0: ffff888025b4af00 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:904
3 locks held by syz-executor/9689:
#0: ffffffff8fc3a2f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8fc3a108 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
#1: ffffffff8fc3a108 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
#1: ffffffff8fc3a108 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0 net/netlink/genetlink.c:1208
#2: ffffffff8fbcc688 (rtnl_mutex){+.+.}-{4:4}, at: wg_set_device_doit+0x170/0x2070 drivers/net/wireguard/netlink.c:484
9 locks held by syz-executor/9791:
#0: ffff88803519e420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88803519e420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
#1: ffff88818a5c6088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
#2: ffff888028b86788 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888028b86788 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
#3: ffffffff8f441228 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff888055cad0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff888055cad0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff888055cad0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304
#5: ffff888055cac250 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1778
#6: ffffffff8fbcc688 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1177
#7: ffff888055270d40 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2784 [inline]
#7: ffff888055270d40 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x583/0x2370 net/core/dev.c:12361
#8: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#8: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.7.825/9797:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
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: 5887 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events free_obj_work
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x5c/0xb0 kernel/rcu/tree.c:752
Code: c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 4c 0b 85 00 48 c7 c3 58 f9 1c 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 <75> 34 8b 03 65 ff 0d 59 1a 71 11 74 11 83 e0 04 c1 e8 02 5b 41 5e
RSP: 0018:ffffc900031c7518 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8880b8633958 RCX: 0000000080000001
RDX: 0000000037dd57dd RSI: ffffffff8c27a9e0 RDI: ffffffff8c27a9a0
RBP: dffffc0000000000 R08: ffffffff81767a45 R09: ffffffff8e7602e0
R10: dffffc0000000000 R11: ffffffff81b0b100 R12: 1ffff92000638ec1
R13: ffffc900031c7640 R14: ffffffff8e1aa790 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125464000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b8ce5a25d0 CR3: 0000000070e21000 CR4: 0000000000350ef0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:851 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd4/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2687 [inline]
slab_free mm/slub.c:6124 [inline]
kmem_cache_free+0x187/0x630 mm/slub.c:6254
free_object_list lib/debugobjects.c:326 [inline]
free_obj_work+0x391/0x4c0 lib/debugobjects.c:513
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245