INFO: task syz.3.527:11225 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.527 state:D stack:27816 pid:11225 tgid:11212 ppid:9967 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:914 [inline]
filename_create+0x1f8/0x3c0 fs/namei.c:4139
do_mkdirat+0xa0/0x590 fs/namei.c:4391
__do_sys_mkdirat fs/namei.c:4416 [inline]
__se_sys_mkdirat fs/namei.c:4414 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4414
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: 0033:0x7fc6c8bed457
RSP: 002b:00007fc6c6e0be68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fc6c6e0bef0 RCX: 00007fc6c8bed457
RDX: 00000000000001ff RSI: 0000200000000000 RDI: 00000000ffffff9c
RBP: 0000200000000040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000040 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fc6c6e0beb0 R14: 0000000000000000 R15: 0000200000002280
Showing all locks held in the system:
1 lock held by khungtaskd/39:
#0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/57:
#0: ffff88814d4ef138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88814d4ef138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000123fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000123fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194
4 locks held by kworker/u8:4/67:
4 locks held by kworker/u8:7/1123:
#0: ffff8881404ca938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff8881404ca938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90004fd7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90004fd7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88802c99c0d0 (&type->s_umount_key#115){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88805d6af7a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
2 locks held by dhcpcd/5497:
#0: ffffffff8ecb6598 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1321
#1: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:577
2 locks held by getty/5593:
#0: ffff88823bf7c8a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:3/5843:
#0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900049ffbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900049ffbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
4 locks held by kworker/u8:11/6460:
3 locks held by kworker/u8:2/9175:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90005077bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90005077bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by syz.3.527/11213:
2 locks held by syz.3.527/11225:
#0: ffff88802c99c488 (sb_writers#31){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff88805d6afb78 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
#1: ffff88805d6afb78 (&type->i_mutex_dir_key#21/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4139
1 lock held by syz-executor/11499:
#0: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3433
4 locks held by syz-executor/11631:
#0: ffff8880343fa488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff8880343fa488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805dd56c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325
#2: ffff888026f72878 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8e542098 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
7 locks held by syz-executor/11642:
#0: ffff8880343fa488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff8880343fa488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805cb8a878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325
#2: ffff888026f72968 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8e542098 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff88804d5890d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88804d5890d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff88804d5890d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffff88804d58b300 (&devlink->lock_key#74){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
#6: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142
4 locks held by syz-executor/11655:
#0: ffff8880343fa488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff8880343fa488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88804dfab478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325
#2: ffff888026f72968 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8e542098 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
1 lock held by syz-executor/11689:
#0: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
1 lock held by syz-executor/11692:
#0: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd20b8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_release+0x89/0x3e0 kernel/locking/lockdep.c:5881
Code: 55 81 0d 00 0f 84 44 02 00 00 65 8b 05 40 1f 5a 10 85 c0 0f 85 35 02 00 00 65 4c 8b 3c 25 08 e0 f5 91 41 83 bf 1c 0b 00 00 00 <0f> 85 1e 02 00 00 49 81 3e 00 83 b9 92 0f 84 11 02 00 00 48 c7 44
RSP: 0018:ffffc90000a3ee90 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8fa73001 RCX: a85a18a3f2a42400
RDX: ffffc90000a3f001 RSI: ffffffff8b620de0 RDI: ffffffff8b620da0
RBP: dffffc0000000000 R08: ffffc90000a3fcf0 R09: 0000000000000000
R10: ffffc90000a3f018 R11: fffff52000147e05 R12: ffffc90000a3fd00
R13: ffffffff8172b165 R14: ffffffff8d9a8b80 R15: ffff88801caa1dc0
FS: 0000000000000000(0000) GS:ffff8881269c2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87b3e65000 CR3: 00000000356c6000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 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
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x1a8/0x320 mm/slub.c:4396
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
ref_tracker_alloc+0x13b/0x450 lib/ref_tracker.c:271
__netdev_tracker_alloc include/linux/netdevice.h:4349 [inline]
netdev_hold include/linux/netdevice.h:4378 [inline]
dst_init+0xd9/0x450 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:93
ip6_dst_alloc net/ipv6/route.c:342 [inline]
icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3324
ndisc_send_skb+0x41f/0x1440 net/ipv6/ndisc.c:491
addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4037
call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x648/0x970 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x22c/0x710 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1043
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245