INFO: task syz.6.667:11012 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.667 state:D stack:28288 pid:11012 tgid:11010 ppid:9346 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x147b/0x4f50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245
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 include/linux/fs.h:1027 [inline]
open_last_lookups fs/namei.c:4546 [inline]
path_openat+0xb65/0x3e70 fs/namei.c:4793
do_filp_open+0x22d/0x490 fs/namei.c:4823
do_sys_openat2+0x12f/0x220 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_creat fs/open.c:1514 [inline]
__se_sys_creat fs/open.c:1508 [inline]
__x64_sys_creat+0x8f/0xc0 fs/open.c:1508
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f284b0eacb9
RSP: 002b:00007f2849325028 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f284b366090 RCX: 00007f284b0eacb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000e00
RBP: 00007f284b158bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f284b366128 R14: 00007f284b366090 R15: 00007ffe6481a598
INFO: task syz.6.667:11013 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.667 state:D stack:28952 pid:11013 tgid:11010 ppid:9346 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x147b/0x4f50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245
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:1072 [inline]
__start_dirop fs/namei.c:2873 [inline]
start_dirop fs/namei.c:2884 [inline]
filename_create+0x200/0x370 fs/namei.c:4888
do_mkdirat+0xd2/0x4c0 fs/namei.c:5165
__do_sys_mkdirat fs/namei.c:5195 [inline]
__se_sys_mkdirat fs/namei.c:5193 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:5193
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f284b0e9b97
RSP: 002b:00007f2849303e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f2849303ee0 RCX: 00007f284b0e9b97
RDX: 00000000000001ff RSI: 0000200000000100 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000100
R13: 00007f2849303ea0 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:6/84:
2 locks held by kworker/u8:10/1474:
4 locks held by kworker/u8:12/3457:
#0: ffff888140abc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140abc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc9000ce97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000ce97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffff88807afee0d0 (&type->s_umount_key#54){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff888060c4d9a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by dhcpcd/5466:
#0: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x23d/0x370 net/ipv6/addrconf.c:4799
2 locks held by getty/5558:
#0: ffff88814db540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
4 locks held by kworker/u8:18/6022:
#0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88801aa94938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90005acfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90005acfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8ed29560 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670
#3: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0xa10 net/core/dev.c:13037
6 locks held by kworker/1:7/6741:
3 locks held by kworker/u8:21/7430:
#0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc900048dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc900048dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by kworker/u8:24/8282:
#0: ffff88814d954938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814d954938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc9000497fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000497fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194
4 locks held by syz.6.667/11011:
2 locks held by syz.6.667/11012:
#0: ffff88807afee480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline]
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793
2 locks held by syz.6.667/11013:
#0: ffff88807afee480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2873 [inline]
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2884 [inline]
#1: ffff888060c4dd78 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4888
1 lock held by syz-executor/11578:
#0: ffff888026c70a18 (&sighand->siglock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#0: ffff888026c70a18 (&sighand->siglock){+.+.}-{3:3}, at: get_signal+0x244/0x1310 kernel/signal.c:2823
1 lock held by syz-executor/11650:
#0: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5027
4 locks held by syz-executor/11702:
#0: ffff888033afe480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888033afe480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682
#1: ffff88805ea5c878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802722ff08 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802722ff08 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e5a8e78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184
7 locks held by syz-executor/11710:
#0: ffff888033afe480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888033afe480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682
#1: ffff88805fe81878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802722d008 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802722d008 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e5a8e78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff88803a5860d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff88803a5860d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1104 [inline]
#4: ffff88803a5860d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1302
#5: ffff888023fed300 (&devlink->lock_key#34){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1777
#6: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8ed37ef8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2156
4 locks held by syz-executor/11719:
#0: ffff888033afe480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888033afe480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:682
#1: ffff88805f350c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff88802722d008 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802722d008 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e5a8e78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
=============================================
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 01/13/2026
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+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1474 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:preempt_count_sub+0x51/0x170 kernel/sched/core.c:5760
Code: 83 3d 92 e1 7b 17 00 75 25 65 8b 05 79 ad 70 10 89 c1 81 e1 ff ff ff 7f 39 cf 7f 2a 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 <08> c8 74 58 65 8b 05 54 ad 70 10 f7 df 65 01 3d 4b ad 70 10 5b 5d
RSP: 0018:ffffc9000533f8d0 EFLAGS: 00000202
RAX: 0000000080000001 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000003 RSI: ffffffff8d1406f5 RDI: 0000000000000001
RBP: ffffc9000533f9f8 R08: ffffffff8f279f77 R09: 1ffffffff1e4f3ee
R10: dffffc0000000000 R11: fffffbfff1e4f3ef R12: dffffc0000000000
R13: 1ffff92000a67f28 R14: ffff888091538500 R15: ffff888091538500
FS: 0000000000000000(0000) GS:ffff8881268fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f406f5b5ff8 CR3: 0000000035c22000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0x4c/0x80 kernel/locking/spinlock.c:194
unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1454
spin_unlock_bh include/linux/spinlock_rt.h:110 [inline]
__batadv_dat_purge+0x335/0x400 net/batman-adv/distributed-arp-table.c:185
batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246