INFO: task kworker/u8:10:10962 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:10 state:D stack:22176 pid:10962 tgid:10962 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:8)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2dc/0x7b0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75d/0x11a0 fs/fs-writeback.c:1825
writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2054
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2130
wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2241
wb_check_start_all fs/fs-writeback.c:2367 [inline]
wb_do_writeback fs/fs-writeback.c:2393 [inline]
wb_workfn+0x961/0xf60 fs/fs-writeback.c:2426
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
INFO: task syz.8.835:14041 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.835 state:D stack:23752 pid:14041 tgid:14037 ppid:11738 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:1028 [inline]
open_last_lookups fs/namei.c:4586 [inline]
path_openat+0xb5e/0x38a0 fs/namei.c:4833
do_file_open+0x23e/0x4a0 fs/namei.c:4865
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf7652c819
RSP: 002b:00007fcf74786028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fcf767a5fa0 RCX: 00007fcf7652c819
RDX: 0000000000040441 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fcf765c2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000106 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcf767a6038 R14: 00007fcf767a5fa0 R15: 00007ffcf26157b8
</TASK>
INFO: task syz.8.835:14103 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.835 state:D stack:25384 pid:14103 tgid:14037 ppid:11738 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
io_schedule+0x80/0xe0 kernel/sched/core.c:7835
folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870
discard_metapage fs/jfs/jfs_metapage.h:88 [inline]
__get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753
dtSplitPage+0x791/0x37c0 fs/jfs/jfs_dtree.c:1471
dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
dtInsert+0x10a4/0x5f10 fs/jfs/jfs_dtree.c:871
jfs_create+0x75b/0xb10 fs/jfs/namei.c:138
lookup_open fs/namei.c:4489 [inline]
open_last_lookups fs/namei.c:4589 [inline]
path_openat+0x13b4/0x38a0 fs/namei.c:4833
do_file_open+0x23e/0x4a0 fs/namei.c:4865
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_creat fs/open.c:1450 [inline]
__se_sys_creat fs/open.c:1444 [inline]
__x64_sys_creat+0x8f/0xc0 fs/open.c:1444
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf7652c819
RSP: 002b:00007fcf74765028 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fcf767a6090 RCX: 00007fcf7652c819
RDX: 0000000000000000 RSI: 0000000000000018 RDI: 0000200000000e40
RBP: 00007fcf765c2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcf767a6128 R14: 00007fcf767a6090 R15: 00007ffcf26157b8
</TASK>
INFO: task syz.8.835:14104 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.835 state:D stack:24640 pid:14104 tgid:14037 ppid:11738 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1073 [inline]
__start_dirop fs/namei.c:2929 [inline]
start_dirop fs/namei.c:2940 [inline]
filename_create+0x200/0x370 fs/namei.c:4928
filename_mkdirat+0xd2/0x520 fs/namei.c:5265
__do_sys_mkdirat fs/namei.c:5293 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5290
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf7652b687
RSP: 002b:00007fcf74743e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fcf74743ee0 RCX: 00007fcf7652b687
RDX: 00000000000001ff RSI: 00002000000001c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007fcf74743ea0 R14: 0000000000000000 R15: 0000000000000000
</TASK>
INFO: task syz.2.844:14311 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.844 state:D stack:24288 pid:14311 tgid:14310 ppid:9300 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
sync_inodes_sb+0x225/0xc30 fs/fs-writeback.c:2942
__iterate_supers+0x13d/0x290 fs/super.c:927
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:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe90dcfc819
RSP: 002b:00007fe90bf4e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe90df75fa0 RCX: 00007fe90dcfc819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe90df75fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe90df76038 R14: 00007fe90df75fa0 R15: 00007ffcdddadf88
</TASK>
INFO: task syz.2.844:14348 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.844 state:D stack:27936 pid:14348 tgid:14310 ppid:9300 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
__iterate_supers+0x13d/0x290 fs/super.c:927
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:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe90dcfc819
RSP: 002b:00007fe90bf2d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe90df76090 RCX: 00007fe90dcfc819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe90df76090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe90df76128 R14: 00007fe90df76090 R15: 00007ffcdddadf88
</TASK>
INFO: task syz.2.844:14350 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.844 state:D stack:27352 pid:14350 tgid:14310 ppid:9300 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
__iterate_supers+0x13d/0x290 fs/super.c:927
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:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe90dcfc819
RSP: 002b:00007fe90bf0c028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fe90df76180 RCX: 00007fe90dcfc819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe90df76180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe90df76218 R14: 00007fe90df76180 R15: 00007ffcdddadf88
</TASK>
Showing all locks held in the system:
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
8 locks held by kworker/u8:6/138:
2 locks held by getty/5557:
#0: ffff8880375f10a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by udevd/5849:
#0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline]
#0: ffffffff8e4de058 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_perm+0x251/0x560 security/tomoyo/file.c:826
#1: ffffffff8df09b50 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffffffff8df09b50 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:294
#2: ffff8880b893b7e0 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647
4 locks held by kworker/u8:10/10962:
#0: ffff88801eaef138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801eaef138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc9000de5fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc9000de5fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff888040e0e368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by syz-executor/13276:
2 locks held by syz.8.835/14041:
#0: ffff8880312e8480 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833
4 locks held by syz.8.835/14103:
#0: ffff8880312e8480 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833
#2: ffff888040e0e368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_create+0x22e/0xb10 fs/jfs/namei.c:101
#3: ffff888040e0c628 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_create+0x249/0xb10 fs/jfs/namei.c:102
2 locks held by syz.8.835/14104:
#0: ffff8880312e8480 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline]
#1: ffff888040e0e738 (&type->i_mutex_dir_key#17/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928
2 locks held by syz.2.844/14311:
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
2 locks held by syz.2.844/14348:
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
2 locks held by syz.2.844/14350:
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
2 locks held by syz.9.863/15180:
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880312e80d0 (&type->s_umount_key#78){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff8880257a28c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940
4 locks held by syz-executor/17668:
2 locks held by syz.7.1064/18605:
3 locks held by syz.4.1067/18671:
1 lock held by udevadm/18693:
#0: ffff88801e6dee58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#0: ffff88801e6dee58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3750 [inline]
#0: ffff88801e6dee58 (&n->list_lock){+.+.}-{3:3}, at: __refill_objects_node+0x87/0x560 mm/slub.c:7027
7 locks held by udevd/18703:
3 locks held by dhcpcd-run-hook/18704:
=============================================
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 03/18/2026
Call Trace:
<TASK>
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:161 [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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 ee 03 94 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 af 27 fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001679d0 EFLAGS: 00000202
RAX: 1ffffffff332b500 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff9995ad10 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff85308230 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9995aa80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126335000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0bf8546d50 CR3: 0000000059fe8000 CR4: 00000000003526f0
Call Trace:
<TASK>
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1970
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>