INFO: task syz.2.1437:12706 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1437 state:D stack:28776 pid:12706 tgid:12699 ppid:5834 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
blk_trace_remove kernel/trace/blktrace.c:406 [inline]
blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
blkdev_common_ioctl+0xf29/0x2470 block/ioctl.c:630
blkdev_ioctl+0x1cb/0x6d0 block/ioctl.c:699
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f61e6b8f6c9
RSP: 002b:00007f61e4db4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f61e6de6180 RCX: 00007f61e6b8f6c9
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000007
RBP: 00007f61e6c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f61e6de6218 R14: 00007f61e6de6180 R15: 00007ffc1a7f3f68
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:8/3521:
#0: ffff8880b843a4d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
#0: ffff8880b843a4d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
#1: ffff8880b8424088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline]
#1: ffff8880b8424088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6923
#2: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#2: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
#2: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x20a0 arch/x86/kernel/unwind_orc.c:479
#3: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#3: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#3: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule_buff+0xb98/0x14c0 net/batman-adv/bat_iv_ogm.c:849
2 locks held by getty/5589:
#0: ffff8880315520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
2 locks held by syz.2.1437/12702:
1 lock held by syz.2.1437/12706:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
1 lock held by syz.0.1566/13305:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xd7/0x1b0 kernel/trace/blktrace.c:613
1 lock held by syz.0.1566/13310:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
1 lock held by syz.3.1572/13333:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xd7/0x1b0 kernel/trace/blktrace.c:613
1 lock held by syz.3.1572/13339:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
4 locks held by kworker/u8:2/13549:
#0: ffff88801ba9f148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc90000ac7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffffffff900d48d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669
#3: ffffffff900ead08 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1b/0x230 drivers/net/wireguard/device.c:419
1 lock held by syz.4.1611/13560:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xd7/0x1b0 kernel/trace/blktrace.c:613
1 lock held by syz.4.1611/13562:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
1 lock held by syz.1.1624/13645:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xd7/0x1b0 kernel/trace/blktrace.c:613
1 lock held by syz.1.1624/13647:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
1 lock held by syz.6.1627/13662:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xd7/0x1b0 kernel/trace/blktrace.c:613
1 lock held by syz.6.1627/13663:
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:406 [inline]
#0: ffff88802586c408 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x23a/0x280 kernel/trace/blktrace.c:727
1 lock held by syz.5.1664/13944:
#0: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
4 locks held by syz.9.1665/13962:
#0: ffff88808a208dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499
#1: ffff88808a2080b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5296
#2: ffffffff9035ec48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2119 [inline]
#2: ffffffff9035ec48 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2614
#3: ffff88808f430b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1763
2 locks held by syz.7.1666/13952:
#0: ffffffff8f429d48 (ubi_devices_mutex){+.+.}-{4:4}, at: ctrl_cdev_ioctl+0x2ed/0x3d0 drivers/mtd/ubi/cdev.c:1112
#1: ffffffff8e3cfa40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3820
1 lock held by syz.7.1666/13955:
#0: ffffffff8f429d48 (ubi_devices_mutex){+.+.}-{4:4}, at: ctrl_cdev_ioctl+0x1ea/0x3d0 drivers/mtd/ubi/cdev.c:1138
2 locks held by syz.8.1667/13958:
#0: ffffffff900ead08 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0x167/0x230 drivers/net/ppp/ppp_generic.c:413
#1: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
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 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
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: 12702 Comm: syz.2.1437 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:stack_trace_consume_entry+0xaf/0x170 kernel/stacktrace.c:93
Code: c0 03 38 d0 7c 08 84 d2 0f 85 98 00 00 00 8b 43 0c 85 c0 75 57 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 <0f> 85 9a 00 00 00 8d 45 01 89 43 10 48 8b 03 48 8d 2c e8 48 b8 00
RSP: 0018:ffffc9000495f840 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc9000495f920 RCX: ffffc9000495f7b4
RDX: 1ffff9200092bf24 RSI: ffffffff82158a7f RDI: ffffc9000495f92c
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000012e1d R12: ffffffff81a76bf0
R13: ffffc9000495f920 R14: 0000000000000000 R15: ffff8880268fbc80
FS: 00007f61e4dd56c0(0000) GS:ffff888124b0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30fe3ff8 CR3: 0000000055108000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x88/0x100 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
__free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
relay_destroy_buf+0x11f/0x3e0 kernel/relay.c:200
relay_remove_buf kernel/relay.c:220 [inline]
kref_put include/linux/kref.h:65 [inline]
relay_close_buf+0x144/0x1a0 kernel/relay.c:435
relay_open+0x765/0xad0 kernel/relay.c:531
do_blk_trace_setup+0x4c5/0xb00 kernel/trace/blktrace.c:572
blk_trace_setup+0xed/0x1b0 kernel/trace/blktrace.c:614
blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:712
blkdev_ioctl+0x108/0x6d0 block/ioctl.c:694
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f61e6b8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f61e4dd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f61e6de6090 RCX: 00007f61e6b8f6c9
RDX: 0000200000000240 RSI: 00000000c0481273 RDI: 0000000000000007
RBP: 00007f61e6c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f61e6de6128 R14: 00007f61e6de6090 R15: 00007ffc1a7f3f68