INFO: task kworker/u8:5:85 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5 state:D stack:21568 pid:85 tgid:85 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:6)
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x147b/0x4f50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
io_schedule+0x80/0xe0 kernel/sched/core.c:7791
TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline]
txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:375
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:1582 [inline]
__writeback_single_inode+0x7e4/0x1230 fs/fs-writeback.c:1802
writeback_sb_inodes+0x92e/0x1910 fs/fs-writeback.c:2030
wb_writeback+0x445/0xad0 fs/fs-writeback.c:2216
wb_do_writeback fs/fs-writeback.c:2363 [inline]
wb_workfn+0x3fd/0xf00 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: task syz-executor:7021 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:21560 pid:7021 tgid:7021 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x147b/0x4f50 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
wb_wait_for_completion+0x372/0x690 fs/fs-writeback.c:226
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2813
sync_filesystem+0xa2/0x250 fs/sync.c:54
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
kill_block_super+0x44/0x90 fs/super.c:1722
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x437/0x4d0 fs/namespace.c:1318
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:44 [inline]
exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0bf5b6bf17
RSP: 002b:00007fff070eacd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f0bf5bd471f RCX: 00007f0bf5b6bf17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff070ead90
RBP: 00007fff070ead90 R08: 00007fff070ebd90 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff070ebe20
R13: 00007f0bf5bd471f R14: 000000000005e464 R15: 00007fff070ebe60
Showing all locks held in the system:
8 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/38:
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d9c7780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/85:
#0: ffff888140463938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888140463938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc900015cfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc900015cfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
1 lock held by kworker/u8:9/1129:
3 locks held by kworker/u8:12/3594:
#0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc9000ebc7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000ebc7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8ed37f78 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by getty/5550:
#0: ffff88814e9c50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:17/5974:
5 locks held by kworker/u8:23/6374:
1 lock held by syz-executor/7021:
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
2 locks held by udevd/8497:
1 lock held by udevd/9177:
1 lock held by syz.8.447/9518:
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121
1 lock held by syz.8.447/9521:
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880288b80d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:121
8 locks held by syz-executor/9748:
2 locks held by syz.5.483/9832:
1 lock held by syz.7.486/9837:
#0: ffff88804aadc0d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
2 locks held by syz.9.488/9849:
3 locks held by syz.0.487/9851:
#0: ffff8880337c60d0 (&type->s_umount_key#27/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
#1: ffff8880337c6770 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
#1: ffff8880337c6770 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
#1: ffff8880337c6770 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs/super.h:177 [inline]
#1: ffff8880337c6770 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x274/0xe60 fs/ext4/inode.c:214
#2: ffffffff8d613778 (bit_wait_table + i){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#2: ffffffff8d613778 (bit_wait_table + i){+.+.}-{3:3}, at: finish_wait kernel/sched/wait.c:394 [inline]
#2: ffffffff8d613778 (bit_wait_table + i){+.+.}-{3:3}, at: __wait_on_bit+0x1fe/0x300 kernel/sched/wait_bit.c:55
2 locks held by cmp/9870:
=============================================
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 01/13/2026
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: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+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9870 Comm: cmp Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:kasan_check_range+0x1c8/0x2c0 mm/kasan/generic.c:200
Code: 49 01 dc 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 0e 41 80 3b 00 75 7c 49 ff c3 49 ff cc 75 f2 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 45 84 ff 0f 85 a1 00
RSP: 0018:ffffc9000e807508 EFLAGS: 00000256
RAX: 1ffffd40003a8f01 RBX: ffffea0001d47900 RCX: ffffffff8228942d
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001d47900
RBP: 0000000000000000 R08: ffffea0001d47907 R09: 1ffffd40003a8f20
R10: dffffc0000000000 R11: fffff940003a8f21 R12: 0000000000000001
R13: dffffc0000000000 R14: fffff940003a8f21 R15: 1ffffd40003a8f20
FS: 0000000000000000(0000) GS:ffff8881267fc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcbfae9de9c CR3: 000000000d7b4000 CR4: 00000000003526f0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
folio_test_head include/linux/page-flags.h:844 [inline]
folio_test_large include/linux/page-flags.h:865 [inline]
folio_nr_pages include/linux/mm.h:2263 [inline]
uncharge_folio+0x25d/0x6b0 mm/memcontrol.c:4889
__mem_cgroup_uncharge_folios+0xfd/0x1d0 mm/memcontrol.c:4930
mem_cgroup_uncharge_folios include/linux/memcontrol.h:691 [inline]
folios_put_refs+0x567/0x680 mm/swap.c:1001
free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:355
__tlb_batch_free_encoded_pages mm/mmu_gather.c:137 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:150 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:398 [inline]
tlb_flush_mmu+0x3a8/0x680 mm/mmu_gather.c:405
tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530
exit_mmap+0x451/0xb30 mm/mmap.c:1290
__mmput+0xcb/0x3d0 kernel/fork.c:1173
exit_mm+0x168/0x220 kernel/exit.c:581
do_exit+0x62e/0x2320 kernel/exit.c:959
do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbfaffc6c5
Code: Unable to access opcode bytes at 0x7fcbfaffc69b.
RSP: 002b:00007ffd65b5e5d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fcbfb0fdfe8 RCX: 00007fcbfaffc6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007ffd65b5e568 R09: 0000000000000000
R10: 00007ffd65b5e400 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcbfb0fc680 R15: 00007fcbfb0fe000