INFO: task syz.7.2075:17503 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.2075 state:D stack:28136 pid:17503 tgid:17502 ppid:16195 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5521 [inline]
__schedule+0x1b57/0x5bc0 kernel/sched/core.c:7272
__schedule_loop kernel/sched/core.c:7349 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7364
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7421
rwsem_down_read_slowpath+0x6ba/0x920 kernel/locking/rwsem.c:1114
__down_read_common kernel/locking/rwsem.c:1291 [inline]
__down_read kernel/locking/rwsem.c:1304 [inline]
down_read+0x9c/0x330 kernel/locking/rwsem.c:1576
__super_lock fs/super.c:62 [inline]
super_lock+0x2d6/0x3d0 fs/super.c:124
__iterate_supers+0x26b/0x420 fs/super.c:994
ksys_sync fs/sync.c:102 [inline]
__ia32_sys_sync+0xa0/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0d6db9e0d9
RSP: 002b:00007f0d6ea5a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f0d6de25fa0 RCX: 00007f0d6db9e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f0d6de25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0d6de26038 R14: 00007f0d6de25fa0 R15: 00007ffee67125f8
Showing all locks held in the system:
locks held by khungtaskd/33: 1, last CPU#1:
#0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by getty/5374: 2, on CPU#0:
#0: ffff8880358640a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:10/5893: 4, on CPU#1:
#0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90004cb7c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004cb7c40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004cb7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90004cb7c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90241d08 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:681
#3: ffffffff90250580 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1710
locks held by kworker/u8:12/7540: 3, on CPU#0:
#0: ffff888020358140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888020358140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888020358140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888020358140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90005f1fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90005f1fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90005f1fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90005f1fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff90250580 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
#2: ffffffff90250580 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x116/0x15c0 net/ipv6/addrconf.c:4230
locks held by syz.5.1311/12944: 2, on CPU#1:
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:631
#1: ffffffff8f09e740 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by kworker/u8:2/17472: 2, last CPU#0:
#0: ffff8880b863bc20 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:686
#1: ffff8880b8624508 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x57/0x7d0 kernel/sched/psi.c:933
locks held by syz.7.2075/17503: 1, on CPU#0:
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124
locks held by syz-executor/19149: 6, last CPU#0:
#0: ffff8880767280e8 (&type->s_umount_key#97){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880767280e8 (&type->s_umount_key#97){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff8880767280e8 (&type->s_umount_key#97){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:631
#1: ffff888029f85a50 (&sbi->umount_mutex){+.+.}-{4:4}, at: f2fs_put_super+0x10c/0x14c0 fs/f2fs/super.c:1995
#2: ffff888029f84330 (&sbi->cp_global_sem_key){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2462 [inline]
#2: ffff888029f84330 (&sbi->cp_global_sem_key){+.+.}-{4:4}, at: f2fs_down_write_trace+0x34/0x1f0 fs/f2fs/checkpoint.c:180
#3: ffff888029f843d0 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2462 [inline]
#3: ffff888029f843d0 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_lock_all fs/f2fs/checkpoint.c:222 [inline]
#3: ffff888029f843d0 (&sbi->cp_rwsem){++++}-{4:4}, at: block_operations fs/f2fs/checkpoint.c:1448 [inline]
#3: ffff888029f843d0 (&sbi->cp_rwsem){++++}-{4:4}, at: f2fs_write_checkpoint+0x677/0x2710 fs/f2fs/checkpoint.c:1905
#4: ffff888029f84470 (&sbi->node_write){++++}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2462 [inline]
#4: ffff888029f84470 (&sbi->node_write){++++}-{4:4}, at: block_operations fs/f2fs/checkpoint.c:1498 [inline]
#4: ffff888029f84470 (&sbi->node_write){++++}-{4:4}, at: f2fs_write_checkpoint+0xf02/0x2710 fs/f2fs/checkpoint.c:1905
#5: ffff888058bd6170 (&io->io_rwsem){++++}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2462 [inline]
#5: ffff888058bd6170 (&io->io_rwsem){++++}-{4:4}, at: f2fs_down_write_trace+0x34/0x1f0 fs/f2fs/checkpoint.c:180
locks held by syz.9.2336/19280: 1, on CPU#1:
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
#0: ffff88807b5700e8 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124
locks held by syz-executor/19906: 10, last CPU#1:
#0: ffff8880338ca460 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff8880338ca460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#1: ffff888032424c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
#2: ffff8880295ca968 (kn->active#51){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff8880295ca968 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
#3: ffffffff8fac8400 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff888027426128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff888027426128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#4: ffff888027426128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
#5: ffff88802b934258 (&devlink->lock_key#15){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1724
#6: ffffffff90250580 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1193
#7: ffffffff9aedc608 (&net->mpls.platform_mutex){+.+.}-{4:4}, at: mpls_dev_notify+0x82/0xd30 net/mpls/af_mpls.c:1648
#8: ffffffff8eeabf30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
#8: ffffffff8eeabf30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:305
#9: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#9: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#9: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#9: ffffffff8ed5ca60 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.4.2413/20089: 2, last CPU#1:
#0: ffff88801c2f8460 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88801c2f8460 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#1: ffff8880262720b0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff8880262720b0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3430
locks held by syz.3.2362/20094: 4, last CPU#0:
#0: ffff88803370f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffff88803370f128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: tty_write_lock drivers/tty/tty_io.c:939 [inline]
#1: ffff88803370f128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: iterate_tty_write drivers/tty/tty_io.c:958 [inline]
#1: ffff88803370f128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: file_tty_write+0x1e2/0x9f0 drivers/tty/tty_io.c:1054
#2: ffff88803370f2c8 (&tty->termios_rwsem){++++}-{4:4}, at: lock_hrtimer_base kernel/time/hrtimer.c:192 [inline]
#2: ffff88803370f2c8 (&tty->termios_rwsem){++++}-{4:4}, at: hrtimer_start_range_ns+0x8c/0x3e0 kernel/time/hrtimer.c:1529
#3: ffffffff9aa20788 (&____s->seqcount#2){----}-{0:0}, at: ktime_get+0x45/0x220 kernel/time/timekeeping.c:1002
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 4972 Comm: klogd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0033:0x7f4da04ed4e0
Code: 84 99 fe ff ff f3 0f bc c0 31 c9 40 3a 34 02 75 c4 48 01 d0 e9 15 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 f9 6e c6 89 f8 25 ff 0f 00 00 c4 e2 7d 78 c0 c5 f1 ef c9 3d e0
RSP: 002b:00007fff912bf068 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 00007f4da0635704 RCX: 00007f4da0461de8
RDX: 0000000000000062 RSI: 000000000000000a RDI: 00007f4da0635705
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007f4da0635490
R13: 00007f4da0612dfe R14: 00007f4da0635705 R15: 00007f4da0635705
FS: 00007f4da02cbc80 GS: 0000000000000000