INFO: task kworker/u8:6:8550 blocked in I/O wait for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:20832 pid:8550 tgid:8550 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x16ec/0x5620 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
io_schedule+0x7f/0xd0 kernel/sched/core.c:8110
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:376
jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1584 [inline]
__writeback_single_inode+0x75d/0x10e0 fs/fs-writeback.c:1827
writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241
wb_do_writeback fs/fs-writeback.c:2388 [inline]
wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x388/0x470 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
INFO: task syz-executor:11213 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21848 pid:11213 tgid:11213 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x16ec/0x5620 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847
sync_filesystem+0xa2/0x250 fs/sync.c:54
generic_shutdown_super+0x77/0x2d0 fs/super.c:625
kill_block_super+0x44/0x90 fs/super.c:1725
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f99ea69e097
RSP: 002b:00007fff4269ef98 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f99ea7321ca RCX: 00007f99ea69e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff4269f050
RBP: 00007fff4269f050 R08: 00007fff426a0050 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff426a00e0
R13: 00007f99ea7321ca R14: 00000000000a686c R15: 00007fff426a0120
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:3/56:
3 locks held by kworker/0:2/824:
#0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc900052d7c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc900052d7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
3 locks held by kworker/u8:14/4288:
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90010b7fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90010b7fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by udevd/4964:
1 lock held by dhcpcd/5259:
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x2[ 837.592578][ T38] #0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x2[ 837.592578][ T38] #0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x23d/0x370 net/ipv6/addrconf.c:4811
2 locks held by getty/5353:
#0: ffff88803239a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by kworker/0:3/5606:
#0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc900050f7c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc900050f7c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
3 locks held by kworker/0:4/5615:
#0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90005177c40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90005177c40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x450 net/core/dev_addr_lists.c:1312
2 locks held by kworker/u8:6/8550:
#0: ffff88801f2f7938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801f2f7938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90005a77c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90005a77c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
1 lock held by syz-executor/11213:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
1 lock held by udevd/11329:
#0: ffff888037496480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
1 lock held by syz.1.640/12612:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12613:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12614:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12615:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12616:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12617:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12618:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.1.640/12619:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz.0.643/12710:
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880274260d0 (&type->s_umount_key#98){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
1 lock held by syz-executor/12970:
1 lock held by udevd/13232:
1 lock held by syz-executor/14380:
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
4 locks held by syz.6.796/14516:
2 locks held by syz.3.794/14519:
4 locks held by syz.7.797/14523:
#0: ffff88802c18a480 (sb_writers#26){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88823bf4e2c0 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
#1: ffff88823bf4e2c0 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline]
#1: ffff88823bf4e2c0 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline]
#1: ffff88823bf4e2c0 (&type->i_mutex_dir_key#18/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4950
#2: ffff88802c18a770 (sb_internal#5){.+.+}-{0:0}, at: nilfs_mkdir+0xd6/0x340 fs/nilfs2/namei.c:228
#3: ffff88802a7302b0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221
=============================================
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 04/18/2026
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:162 [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+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 4964 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__lock_acquire+0x0/0x2cf0 kernel/locking/lockdep.c:5081
Code: 48 89 de ba 08 00 00 00 b9 0a 00 00 00 5b e9 c7 55 00 00 5b e9 41 c2 80 09 cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 48 81 ec e8 00 00 00 65 48 8b 05 57
RSP: 0018:ffffc90003c66f88 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8dfc8080
RBP: ffffffff8176d226 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003c67178 R11: ffffffff81af9590 R12: 0000000000000002
R13: ffffffff8dfc8080 R14: 0000000000000000 R15: 0000000000000246
FS: 00007fce204a0880(0000) GS:ffff888126171000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002640 CR3: 0000000038b68000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6250 [inline]
kfree+0x1c5/0x6c0 mm/slub.c:6565
tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776
security_file_open+0xa9/0x240 security/security.c:2739
do_dentry_open+0x4c0/0x13e0 fs/open.c:924
vfs_open+0x3b/0x350 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e43/0x38a0 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce205fcc3a
Code: 41 89 f2 48 89 54 24 e0 41 83 e2 40 75 2a 89 f0 f7 d0 a9 00 00 41 00 74 1f 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 2e c3 0f 1f 44 00 00 48 8d 44 24 08 c7 44 24
RSP: 002b:00007ffd86d30948 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00005579b05cf060 RCX: 00007fce205fcc3a
RDX: 0000000000090800 RSI: 00005579b057ddd0 RDI: 00000000ffffff9c
RBP: 00005579b057ddd0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 00005579b057b7b0
R13: 00000000000000fd R14: 0000557977db0be0 R15: 00007ffd86d30c60