INFO: task syz.5.435:9258 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.435 state:D stack:27464 pid:9258 tgid:9236 ppid:7622 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:979 [inline]
open_last_lookups fs/namei.c:3892 [inline]
path_openat+0x8e6/0x3840 fs/namei.c:4131
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc169deec9
RSP: 002b:00007fdc14c25038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fdc16c36090 RCX: 00007fdc169deec9
RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fdc16a61f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdc16c36128 R14: 00007fdc16c36090 R15: 00007fff553766a8
INFO: task syz.5.435:9259 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.435 state:D stack:26952 pid:9259 tgid:9236 ppid:7622 task_flags:0x400040 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1024 [inline]
filename_create+0x1f8/0x3c0 fs/namei.c:4226
do_mkdirat+0xa0/0x590 fs/namei.c:4478
__do_sys_mkdirat fs/namei.c:4503 [inline]
__se_sys_mkdirat fs/namei.c:4501 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc169dd617
RSP: 002b:00007fdc14c03e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fdc14c03ef0 RCX: 00007fdc169dd617
RDX: 00000000000001ff RSI: 0000200000000280 RDI: 00000000ffffff9c
RBP: 0000200000000300 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000200000000300 R11: 0000000000000246 R12: 0000200000000280
R13: 00007fdc14c03eb0 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/38:
#0: ffffffff8d3a9d40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d3a9d40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d3a9d40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:3/57:
4 locks held by kworker/u8:6/1105:
4 locks held by kworker/u8:14/4855:
#0: ffff8881404bb138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff8881404bb138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90010557bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90010557bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff888037f7e0d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88803d6032a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
2 locks held by dhcpcd/5479:
#0: ffff88802b032910 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2269
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6814
2 locks held by getty/5576:
#0: ffff88823bf2c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
4 locks held by syz.5.435/9237:
2 locks held by syz.5.435/9258:
#0: ffff888037f7e488 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500
#1: ffff88803d603678 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline]
#1: ffff88803d603678 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline]
#1: ffff88803d603678 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131
2 locks held by syz.5.435/9259:
#0: ffff888037f7e488 (sb_writers#27){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500
#1: ffff88803d603678 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1024 [inline]
#1: ffff88803d603678 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4226
3 locks held by kworker/u8:7/9912:
#0: ffff888019481138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019481138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000dd27bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000dd27bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
7 locks held by syz-executor/9923:
#0: ffff8880345c8488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3101 [inline]
#0: ffff8880345c8488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805b2ea478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888026326d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888026326d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ded5938 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff88803c9b40d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88803c9b40d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff88803c9b40d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffff888051074300 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
#6: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xe5/0x670 drivers/net/netdevsim/netdev.c:1135
4 locks held by syz-executor/10053:
#0: ffff8880345c8488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3101 [inline]
#0: ffff8880345c8488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805d8b8078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888026326d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888026326d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ded5938 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
2 locks held by syz-executor/10280:
#0: ffffffff8ddce360 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ddce360 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8ddce360 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
2 locks held by syz-executor/10334:
#0: ffffffff8e6593a0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160
2 locks held by syz-executor/10351:
#0: ffffffff8e6593a0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576
#1: ffffffff8e6662f8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160
2 locks held by syz.1.573/10423:
1 lock held by syz-executor/10424:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: kvfree_rcu_reclaim kfree_rcu_work
RIP: 0010:__rcu_read_unlock+0x63/0xe0 kernel/rcu/tree_plugin.h:443
Code: 75 1d 4c 8d b7 48 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 66 41 83 3e 00 75 27 43 0f b6 04 3c 84 c0 75 41 8b 03 <3d> 00 00 00 40 73 0f 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc cc
RSP: 0018:ffffc90000117468 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88801a6f5d84 RCX: 1170b0f94c07c700
RDX: 0000000000000003 RSI: ffffffff8cd89977 RDI: ffff88801a6f5940
RBP: dffffc0000000000 R08: ffffc90000117a70 R09: 0000000000000000
R10: ffffc900001175b8 R11: fffff52000022eb9 R12: 1ffff110034debb0
R13: ffffc90000110000 R14: ffff88801a6f5d88 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888127025000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3739a15000 CR3: 0000000037c64000 CR4: 00000000003526f0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:873 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19ae/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2422 [inline]
slab_free_freelist_hook mm/slub.c:2451 [inline]
slab_free_bulk mm/slub.c:4719 [inline]
kmem_cache_free_bulk+0x29c/0x620 mm/slub.c:5298
kfree_bulk include/linux/slab.h:794 [inline]
kvfree_rcu_bulk+0xe5/0x1f0 mm/slab_common.c:1516
kfree_rcu_work+0xed/0x170 mm/slab_common.c:1594
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245