INFO: task kworker/u8:0:12 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:21216 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
writeback_get_folio mm/page-writeback.c:2462 [inline]
writeback_iter+0x8d8/0x1280 mm/page-writeback.c:2556
mpage_writepages+0xee/0x1cc0 fs/mpage.c:669
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0xad7/0xee0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task kworker/u8:6:167 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:6 state:D stack:24280 pid:167 tgid:167 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
writeback_get_folio mm/page-writeback.c:2462 [inline]
writeback_iter+0x8d8/0x1280 mm/page-writeback.c:2556
mpage_writepages+0xee/0x1cc0 fs/mpage.c:669
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0xad7/0xee0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task kworker/u8:14:3502 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:14 state:D stack:21216 pid:3502 tgid:3502 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
writeback_get_folio mm/page-writeback.c:2462 [inline]
writeback_iter+0x8d8/0x1280 mm/page-writeback.c:2556
mpage_writepages+0xee/0x1cc0 fs/mpage.c:669
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0xad7/0xee0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task kworker/u8:15:3528 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:15 state:D stack:24024 pid:3528 tgid:3528 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
writeback_get_folio mm/page-writeback.c:2462 [inline]
writeback_iter+0x8d8/0x1280 mm/page-writeback.c:2556
mpage_writepages+0xee/0x1cc0 fs/mpage.c:669
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0xad7/0xee0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task kworker/u8:20:4026 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:20 state:D stack:21216 pid:4026 tgid:4026 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x81/0xe0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
writeback_get_folio mm/page-writeback.c:2462 [inline]
writeback_iter+0x8d8/0x1280 mm/page-writeback.c:2556
mpage_writepages+0xee/0x1cc0 fs/mpage.c:669
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x8c8/0x1840 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0xad7/0xee0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90000117bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000117bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff8880269b40d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
4 locks held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:5/142:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90003a27bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90003a27bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888058c6e0d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:6/167:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90003a17bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90003a17bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff8880290040d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:9/1400:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000518fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000518fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff8880570980d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:13/3445:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000cd07bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000cd07bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88805b5280d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:14/3502:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000cd27bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000cd27bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888027f080d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:15/3528:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000cf47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000cf47bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88805b34a0d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:18/3875:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000d717bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000d717bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888054aae0d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by kworker/u8:20/4026:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000db87bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000db87bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888025d440d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
1 lock held by klogd/5163:
2 locks held by getty/5564:
#0: ffff88814e04a0a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211
3 locks held by syz.0.17/6092:
3 locks held by syz.2.19/6095:
#0: ffff888027f08480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888027f08480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff88805769ac88 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88805769ac88 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
3 locks held by syz.4.21/6096:
#0: ffff888029004480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888029004480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff88805769ba68 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88805769ba68 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
2 locks held by syz.3.20/6097:
3 locks held by syz.1.18/6098:
#0: ffff88805b34a480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff88805b34a480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff888057665d18 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff888057665d18 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
3 locks held by kworker/u8:22/6218:
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814046d138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000521fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000521fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88802ef180d0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
3 locks held by syz.5.22/6242:
#0: ffff888058c6e480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888058c6e480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff88805769eaf8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88805769eaf8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
3 locks held by syz.8.25/6243:
#0: ffff88802ef18480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff88802ef18480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff8880591310c8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff8880591310c8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
3 locks held by syz.9.26/6246:
#0: ffff888057098480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888057098480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff888059133378 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff888059133378 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
3 locks held by syz.6.23/6248:
#0: ffff888054aae480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff888054aae480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff888057666af8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff888057666af8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
3 locks held by syz.7.24/6251:
#0: ffff88805b528480 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline]
#0: ffff88805b528480 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x5f9/0x7f0 fs/open.c:338
#1: ffff8880576671e8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff8880576671e8 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fat_fallocate+0xf7/0x2f0 fs/fat/file.c:279
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d7c3758 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
4 locks held by syz.3.922/7305:
4 locks held by syz.2.923/7306:
1 lock held by syz.4.924/7307:
2 locks held by syz.0.925/7308:
=============================================
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 10/25/2025
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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</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 10/25/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 2e da b5 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 9f 13 18 fd 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:ffffc90000167950 EFLAGS: 00000202
RAX: 1ffffffff31f3700 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff98f9c010 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8509d2a0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff98f9bd80 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126cee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000d3a8000 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:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3109 [inline]
console_flush_one_record+0x685/0xb80 kernel/printk/printk.c:3215
legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>