INFO: task syz.0.123:6660 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.123 state:D stack:29024 pid:6660 tgid:6606 ppid:5807 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
filename_create+0x200/0x370 fs/namei.c:4922
filename_mknodat+0x18c/0x670 fs/namei.c:5130
__do_sys_mknod fs/namei.c:5179 [inline]
__se_sys_mknod+0x3a/0x150 fs/namei.c:5176
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: 0033:0x7f357f0bc799
RSP: 002b:00007f357d2cc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f357f336180 RCX: 00007f357f0bc799
RDX: 0000000000000701 RSI: 0000000000000004 RDI: 0000200000000000
RBP: 00007f357f152c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f357f336218 R14: 00007f357f336180 R15: 00007ffc4713ccb8
INFO: task syz.0.123:6662 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.123 state:D stack:26528 pid:6662 tgid:6606 ppid:5807 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2923 [inline]
start_dirop fs/namei.c:2934 [inline]
filename_create+0x200/0x370 fs/namei.c:4922
filename_linkat+0x17c/0x600 fs/namei.c:5798
__do_sys_link fs/namei.c:5847 [inline]
__se_sys_link+0x55/0x2c0 fs/namei.c:5843
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: 0033:0x7f357f0bc799
RSP: 002b:00007f357cea9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007f357f336270 RCX: 00007f357f0bc799
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 00002000000001c0
RBP: 00007f357f152c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f357f336308 R14: 00007f357f336270 R15: 00007ffc4713ccb8
Showing all locks held in the system:
3 locks held by kworker/0:0/9:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/43:
#0: ffff88801aabc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801aabc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90000b47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90000b47c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff8880299f20d0 (&type->s_umount_key#86){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff88804c13e368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
6 locks held by kworker/u8:9/1133:
2 locks held by kworker/u8:11/1355:
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90006907c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90006907c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
2 locks held by kworker/u8:12/1408:
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90006977c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90006977c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
5 locks held by kworker/u8:17/3609:
2 locks held by getty/5555:
#0: ffff888036f080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
5 locks held by syz.0.123/6658:
2 locks held by syz.0.123/6660:
#0: ffff8880299f2480 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922
2 locks held by syz.0.123/6662:
#0: ffff8880299f2480 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff88804c13e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922
2 locks held by syz-executor/8363:
#0: ffffffff8e8b69e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e8b69e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e8b69e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
2 locks held by syz-executor/8409:
#0: ffffffff8f14c400 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146
2 locks held by syz.4.356/8438:
4 locks held by cmp/8457:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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:436
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1133 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__rcu_read_lock+0x38/0x60 kernel/rcu/tree_plugin.h:420
Code: 81 c3 c4 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 8b 03 3d 00 00 00 40 7d 07 <5b> c3 cc cc cc cc cc 90 0f 0b 90 eb f3 89 d9 80 e1 07 80 c1 03 38
RSP: 0018:ffffc90006247508 EFLAGS: 00000283
RAX: 0000000000000002 RBX: ffff888027c004c4 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff813303aa RDI: ffffc900062475e8
RBP: dffffc0000000000 R08: ffffc900062476b0 R09: 0000000000000009
R10: ffffc90006247638 R11: ffffffff81af88b0 R12: 1ffff92000c48ebd
R13: ffffc90006247620 R14: ffffc900062475e8 R15: ffffc90006247f48
FS: 0000000000000000(0000) GS:ffff88812643c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7f46c6b6b0 CR3: 000000000dbba000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:848 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x9e/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:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x185/0x6b0 mm/slub.c:6295
nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
nsim_dev_trap_report_work+0x7fa/0xbc0 drivers/net/netdevsim/dev.c:922
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245