INFO: task syz.5.274:7747 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.274 state:D stack:28616 pid:7747 tgid:7738 ppid:6213 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
__rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:884 [inline]
open_last_lookups fs/namei.c:3806 [inline]
path_openat+0x8d7/0x3840 fs/namei.c:4043
do_filp_open+0x1fa/0x410 fs/namei.c:4073
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: 0033:0x7fd2d3c5ebe9
RSP: 002b:00007fd2c9a84038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd2d3e96180 RCX: 00007fd2d3c5ebe9
RDX: 0000000000000000 RSI: 0000200000000200 RDI: ffffffffffffff9c
RBP: 00007fd2d3ce1e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd2d3e96218 R14: 00007fd2d3e96180 R15: 00007ffe2952a668
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/67:
#0: ffff888030a68938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888030a68938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000152fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000152fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194
4 locks held by kworker/u8:6/1272:
2 locks held by kworker/u8:9/2205:
3 locks held by kworker/u8:11/4538:
#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: ffffc9000f167bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000f167bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by dhcpcd/5499:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4799
2 locks held by getty/5591:
#0: ffff88823bf620a0 (&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+0x444/0x1410 drivers/tty/n_tty.c:2222
4 locks held by kworker/u8:13/7448:
#0: ffff888142ada138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888142ada138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900050cfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900050cfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88803e22e0d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88805ce2d068 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
4 locks held by syz.5.274/7746:
1 lock held by syz.5.274/7747:
#0: ffff88805ce2d438 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline]
#0: ffff88805ce2d438 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: open_last_lookups fs/namei.c:3806 [inline]
#0: ffff88805ce2d438 (&type->i_mutex_dir_key#11){++++}-{4:4}, at: path_openat+0x8d7/0x3840 fs/namei.c:4043
1 lock held by syz-executor/7900:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3433
1 lock held by syz-executor/7903:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
1 lock held by syz-executor/7905:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
4 locks held by syz-executor/7936:
#0: ffff88803475e488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff88803475e488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805d4d2078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325
#2: ffff888027249c38 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8e542278 (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/7939:
#0: ffff88803475e488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
#0: ffff88803475e488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88805efc3078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325
#2: ffff888027249d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8e542278 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff888146bb50d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff888146bb50d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff888146bb50d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffff888146bb7300 (&devlink->lock_key#17){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
#6: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142
1 lock held by syz-executor/7989:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
1 lock held by syz-executor/8004:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
1 lock held by syz-executor/8013:
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8ecd2938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979
=============================================
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 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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 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: 1272 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: netns cleanup_net
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5598 [inline]
RIP: 0010:lock_is_held_type+0xba/0x190 kernel/locking/lockdep.c:5940
Code: 20 0b 00 00 45 31 ff 49 83 ff 31 73 24 48 89 df 4c 89 f6 e8 78 02 00 00 85 c0 75 2a 49 ff c7 49 63 85 18 0b 00 00 48 83 c3 28 <49> 39 c7 7c d8 eb 11 48 c7 c7 90 96 87 8d 4c 89 fe e8 80 59 f8 f9
RSP: 0018:ffffc9000509ef58 EFLAGS: 00000096
RAX: 0000000000000007 RBX: ffff8880270f2930 RCX: 95170f7e4b93b700
RDX: dffffc0000000000 RSI: ffff8880b8823d50 RDI: ffff8880270f2908
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000a13e2c R12: 0000000000000046
R13: ffff8880270f1dc0 R14: ffff8880b8823d50 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8881268c1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559636c55a38 CR3: 000000000d7a6000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
try_to_take_rt_mutex+0x4f/0xb00 kernel/locking/rtmutex.c:1090
rtlock_slowlock_locked+0xd8/0x4010 kernel/locking/rtmutex.c:1839
rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x152/0x2c0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
__local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168
local_bh_disable include/linux/bottom_half.h:20 [inline]
spin_lock_bh include/linux/spinlock_rt.h:87 [inline]
addrconf_ifdown+0x3ab/0x18c0 net/ipv6/addrconf.c:3891
addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
call_netdevice_notifiers net/core/dev.c:2281 [inline]
unregister_netdevice_many_notify+0x14d7/0x1fe0 net/core/dev.c:12166
unregister_netdevice_many net/core/dev.c:12229 [inline]
default_device_exit_batch+0x819/0x890 net/core/dev.c:12733
ops_exit_list net/core/net_namespace.c:204 [inline]
ops_undo_list+0x525/0x990 net/core/net_namespace.c:251
cleanup_net+0x4cb/0x800 net/core/net_namespace.c:682
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245