syzbot


INFO: task hung in perf_event_release_kernel

Status: upstream: reported on 2025/12/21 11:31
Reported-by: syzbot+0903b8c3278adba834e6@syzkaller.appspotmail.com
First crash: 179d, last: 10h17m
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in perf_event_release_kernel 1 1 2397d 2397d 0/1 auto-closed as invalid on 2020/03/24 11:22
upstream INFO: task hung in perf_event_release_kernel perf 1 18 2392d 2393d 0/29 closed as invalid on 2019/11/30 16:54
linux-4.19 INFO: task hung in perf_event_release_kernel 1 1 1469d 1469d 0/1 auto-obsoleted due to no activity on 2022/10/08 09:57
linux-4.19 INFO: task hung in perf_event_release_kernel (2) 1 1 1204d 1204d 0/1 upstream: reported on 2023/03/02 17:10

Sample crash report:
INFO: task syz.1.2:5840 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2         state:D stack:24232 pid:5840  ppid:5776   flags:0x00004004
Call Trace:
 <TASK>
 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
 perf_event_ctx_lock_nested+0x3b9/0x490 kernel/events/core.c:1309
 perf_event_ctx_lock kernel/events/core.c:1322 [inline]
 perf_event_release_kernel+0x1a0/0x8d0 kernel/events/core.c:5405
 perf_release+0x3b/0x40 kernel/events/core.c:5513
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 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+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f12f7d9ce59
RSP: 002b:00007ffc820c9508 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f12f8017da0 RCX: 00007f12f7d9ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f12f8017da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007f12f8017cb0 R11: 0000000000000246 R12: 0000000000015123
R13: 00007f12f801618c R14: 00000000000150d8 R15: 00007f12f8016180
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d132160 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d132160 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d132160 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
6 locks held by kworker/u5:0/51:
 #0: ffff88802fcb9138 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802fcb9138 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc90000bc7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90000bc7d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff88802f8a8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x380 net/bluetooth/hci_sync.c:332
 #3: ffff88802f8a80b8 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x98a/0xec0 net/bluetooth/hci_sync.c:5673
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x165/0x300 net/bluetooth/hci_conn.c:1252
 #5: ffff88803124ab38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1759
3 locks held by kworker/u4:4/59:
 #0: ffff88802c9fd138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802c9fd138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc900015a7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc900015a7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd4/0x1530 net/ipv6/addrconf.c:4176
3 locks held by kworker/1:2/786:
3 locks held by kworker/u4:6/1091:
 #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc9000476fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000476fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
5 locks held by kworker/u5:1/5086:
 #0: ffff88802276bd38 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802276bd38 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc900105efd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc900105efd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff88802f3b0e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x380 net/bluetooth/hci_sync.c:332
 #3: ffff88802f3b00b8 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x98a/0xec0 net/bluetooth/hci_sync.c:5673
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x165/0x300 net/bluetooth/hci_conn.c:1252
2 locks held by getty/5536:
 #0: ffff88814cac30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
5 locks held by kworker/u5:2/5779:
 #0: ffff88802205f538 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802205f538 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc9000454fd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000454fd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff88807d580e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x380 net/bluetooth/hci_sync.c:332
 #3: ffff88807d5800b8 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x98a/0xec0 net/bluetooth/hci_sync.c:5673
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x165/0x300 net/bluetooth/hci_conn.c:1252
4 locks held by kworker/u5:3/5782:
 #0: ffff888025b58138 ((wq_completion)hci12#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888025b58138 ((wq_completion)hci12#2){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc9000465fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000465fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff888041fd40b8 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x9c/0x900 net/bluetooth/hci_event.c:3685
 #3: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #3: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x547/0x900 net/bluetooth/hci_event.c:3719
5 locks held by kworker/u5:4/5783:
 #0: ffff88802d2c0138 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802d2c0138 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc9000469fd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000469fd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff88807d584e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x380 net/bluetooth/hci_sync.c:332
 #3: ffff88807d5840b8 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x98a/0xec0 net/bluetooth/hci_sync.c:5673
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x165/0x300 net/bluetooth/hci_conn.c:1252
3 locks held by kworker/0:5/5818:
 #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: ffffc9000484fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000484fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
2 locks held by kworker/1:4/5820:
3 locks held by kworker/0:6/5836:
 #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888017c71d38 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc9000488fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc9000488fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x92/0xd90 net/wireless/reg.c:2463
3 locks held by kworker/1:5/5839:
1 lock held by syz.1.2/5840:
 #0: ffff8880276f18a8 (&ctx->mutex){+.+.}-{3:3}, at: perf_event_ctx_lock_nested+0x3b9/0x490 kernel/events/core.c:1309
4 locks held by syz.1.2/5841:
1 lock held by syz.0.1/5843:
 #0: ffffffff8d188368 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239
2 locks held by dhcpcd/5847:
 #0: ffff88805d9c1420 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff88805d9c1420 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff88805d9c1420 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420
 #1: ffffffff8d137b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
 #1: ffffffff8d137b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by dhcpcd/5851:
 #0: ffff8880300ed020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff8880300ed020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff8880300ed020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420
1 lock held by dhcpcd/5857:
 #0: ffff88805d9c8e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff88805d9c8e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff88805d9c8e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420
1 lock held by dhcpcd/5858:
 #0: ffff88805d9ca020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff88805d9ca020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff88805d9ca020 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420
1 lock held by syz-executor/5862:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5865:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by dhcpcd/5869:
 #0: ffff88805d9cee20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff88805d9cee20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff88805d9cee20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420
2 locks held by dhcpcd/5870:
 #0: ffff888076f1a620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #0: ffff888076f1a620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
 #0: ffff888076f1a620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420
 #1: ffffffff8d137b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #1: ffffffff8d137b38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz-executor/5873:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5877:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5881:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5886:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5891:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5896:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
1 lock held by syz-executor/5905:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
5 locks held by kworker/u5:6/5907:
 #0: ffff88802c5a8138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802c5a8138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc90005107d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90005107d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff88807d27ce70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x380 net/bluetooth/hci_sync.c:332
 #3: ffff88807d27c0b8 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x98a/0xec0 net/bluetooth/hci_sync.c:5673
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x165/0x300 net/bluetooth/hci_conn.c:1252
1 lock held by syz-executor/5911:
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
 #0: ffffffff8e3c6988 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x811/0xfa0 net/core/rtnetlink.c:6473
4 locks held by kworker/u5:7/5912:
 #0: ffff888026f97538 ((wq_completion)hci13#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff888026f97538 ((wq_completion)hci13#2){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc90005137d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90005137d00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff88805d2540b8 (&hdev->lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x9c/0x900 net/bluetooth/hci_event.c:3685
 #3: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #3: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_remote_features_evt+0x547/0x900 net/bluetooth/hci_event.c:3719
5 locks held by kworker/u5:8/5914:
 #0: ffff88802c5aa138 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88802c5aa138 ((wq_completion)hci4){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc90005147d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc90005147d00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #2: ffff888031410e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x380 net/bluetooth/hci_sync.c:332
 #3: ffff8880314100b8 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x98a/0xec0 net/bluetooth/hci_sync.c:5673
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:1996 [inline]
 #4: ffffffff8e534ca8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_failed+0x165/0x300 net/bluetooth/hci_conn.c:1252

=============================================

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 05/09/2026
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5841 Comm: syz.1.2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_preemption_disabled+0x1/0x110 lib/smp_processor_id.c:13
Code: e9 6e ff ff ff cc cc cc cc f3 0f 1e fa 48 c7 c7 c0 9b 1c 8b 48 c7 c6 00 9c 1c 8b eb 0c 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24
RSP: 0018:ffffc900001f0a28 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 70196920ac0c2a00
RDX: 0000000000000000 RSI: ffffffff8b1c9c00 RDI: ffffffff8b1c9bc0
RBP: 0000000000000000 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f12f8bfe6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c971c984b0 CR3: 000000005cb5f000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x8d/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__mod_timer+0x8c/0xdb0 kernel/time/timer.c:1027
Code: 41 83 fc 04 48 89 1c 24 73 70 4c 8d 6b 08 4c 89 ed 48 c1 ed 03 42 80 7c 35 00 00 74 08 4c 89 ef e8 e9 f6 68 00 49 83 7d 00 00 <74> 55 48 8b 04 24 48 8d 58 10 48 89 d8 48 c1 e8 03 48 89 44 24 20
RSP: 0018:ffffc900001f0b28 EFLAGS: 00000246
RAX: ffffffff817674a2 RBX: ffff88805dc1ed88 RCX: 0000000000000100
RDX: ffff888021133c00 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 1ffff1100bb83db2 R08: ffffffff911cd5f7 R09: 1ffffffff2239abe
R10: dffffc0000000000 R11: fffffbfff2239abf R12: 0000000000000000
R13: ffff88805dc1ed90 R14: dffffc0000000000 R15: 00000000ffffebb5
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x542/0x800 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5255
Code: 0f 84 33 01 00 00 48 85 db 0f 85 52 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 e0 94 34 09 e8 1b 2f 30 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900048ff758 EFLAGS: 00000282
RAX: 70196920ac0c2a00 RBX: 0000000000000000 RCX: 70196920ac0c2a00
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9c20
RBP: ffffc900048ff7b0 R08: ffffffff911cd5ff R09: 1ffffffff2239abf
R10: dffffc0000000000 R11: fffffbfff2239ac0 R12: ffff888021133c00
R13: dffffc0000000000 R14: ffff88802c499e00 R15: ffff8880b8f3cb48
 context_switch kernel/sched/core.c:5384 [inline]
 __schedule+0x155b/0x45a0 kernel/sched/core.c:6700
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 smp_call_function_single+0x48d/0x5a0 kernel/smp.c:652
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959
 __do_sys_perf_event_open kernel/events/core.c:12957 [inline]
 __se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12609
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f12f7d9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f12f8bfe028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f12f8015fa0 RCX: 00007f12f7d9ce59
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007f12f7e32d6f R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f12f8016038 R14: 00007f12f8015fa0 R15: 00007ffc820c93a8
 </TASK>

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/18 08:46 linux-6.6.y 924b4a879cbb b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/06/11 05:35 linux-6.6.y 924b4a879cbb b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/05/30 04:26 linux-6.6.y 0a40c6fbd105 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/04/19 02:49 linux-6.6.y 9760bf04666d 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/04/03 13:27 linux-6.6.y 08667c1437c0 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/03/17 15:26 linux-6.6.y 4fc00fe35d46 c01bca74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/02/05 04:34 linux-6.6.y 2cf6f68313dc ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2026/02/03 18:08 linux-6.6.y 2cf6f68313dc 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2025/12/26 15:12 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
2025/12/21 11:30 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: task hung in perf_event_release_kernel
* Struck through repros no longer work on HEAD.