INFO: task kworker/u8:4:58 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4 state:D stack:23176 pid:58 tgid:58 ppid:2 task_flags:0x4248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
io_schedule+0x8a/0xf0 kernel/sched/core.c:7831
rq_qos_wait+0x22d/0x330 block/blk-rq-qos.c:307
__wbt_wait block/blk-wbt.c:598 [inline]
wbt_wait+0x18a/0x310 block/blk-wbt.c:658
__rq_qos_throttle+0x56/0xa0 block/blk-rq-qos.c:66
rq_qos_throttle block/blk-rq-qos.h:164 [inline]
rq_qos_throttle block/blk-rq-qos.h:160 [inline]
blk_mq_get_new_requests block/blk-mq.c:3063 [inline]
blk_mq_submit_bio+0xb68/0x2bf0 block/blk-mq.c:3214
__submit_bio+0x1e1/0x6c0 block/blk-core.c:635
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
ext4_io_submit+0xf7/0x1a0 fs/ext4/page-io.c:405
io_submit_add_bh fs/ext4/page-io.c:446 [inline]
ext4_bio_write_folio+0x766/0x1dd0 fs/ext4/page-io.c:590
mpage_process_page_bufs+0x473/0x8d0 fs/ext4/inode.c:2191
mpage_prepare_extent_to_map+0xb50/0x1920 fs/ext4/inode.c:2730
ext4_do_writepages+0x9f9/0x3f50 fs/ext4/inode.c:2871
ext4_writepages+0x347/0x790 fs/ext4/inode.c:3019
do_writepages+0x278/0x600 mm/page-writeback.c:2554
__writeback_single_inode+0x164/0x13c0 fs/fs-writeback.c:1750
writeback_sb_inodes+0x72e/0x1bf0 fs/fs-writeback.c:2041
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2118
wb_writeback+0x755/0xbe0 fs/fs-writeback.c:2229
wb_check_old_data_flush fs/fs-writeback.c:2333 [inline]
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0x8c6/0xc00 fs/fs-writeback.c:2414
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.0.202:6792 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.202 state:D stack:28440 pid:6792 tgid:6792 ppid:6284 task_flags:0x440040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
io_schedule+0x8a/0xf0 kernel/sched/core.c:7831
bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250
__wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52
out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67
wait_on_bit_io include/linux/wait_bit.h:105 [inline]
do_get_write_access+0x889/0x1210 fs/jbd2/transaction.c:1092
jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1242
__ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241
ext4_reserve_inode_write+0x1b7/0x330 fs/ext4/inode.c:6238
__ext4_mark_inode_dirty+0x18f/0x8b0 fs/ext4/inode.c:6413
ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6450
__mark_inode_dirty+0x1f3/0x1790 fs/fs-writeback.c:2609
generic_update_time fs/inode.c:2198 [inline]
file_update_time_flags+0x46b/0x500 fs/inode.c:2428
ext4_page_mkwrite+0x35b/0x1980 fs/ext4/inode.c:6616
do_page_mkwrite+0x17a/0x440 mm/memory.c:3589
do_shared_fault mm/memory.c:5874 [inline]
do_fault+0x3d7/0x1950 mm/memory.c:5936
do_pte_missing mm/memory.c:4477 [inline]
handle_pte_fault mm/memory.c:6316 [inline]
__handle_mm_fault+0x180f/0x2b60 mm/memory.c:6454
handle_mm_fault+0x36d/0xa20 mm/memory.c:6623
do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f9978066bcb
RSP: 002b:00007ffc661cabc0 EFLAGS: 00010246
RAX: 000000000003fde8 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000001b2c720000 RSI: 0000000000040000 RDI: 00007f997838a710
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000021fd0 R15: 00007ffc661cae50
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/58:
#0: ffff888020ab7148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc900015f7d08 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffff8880368bc0e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:565
#3: ffff8880368bab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2554
1 lock held by klogd/5180:
#0: ffff8880b843b2e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:647
2 locks held by getty/5580:
#0: ffff8880378b20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by syz.0.202/6792:
#0: ffff88802ab8fe48 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x11d/0x590 mm/mmap_lock.c:310
#1: ffff8880368bc518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x440 mm/memory.c:3589
#2: ffff8880368b8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
3 locks held by syz-executor/6793:
#0: ffff8880368bc420 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10d/0x400 fs/namei.c:4915
#1: ffff888076929710 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff888076929710 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff888076929710 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff888076929710 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1c0/0x400 fs/namei.c:4922
#2: ffff8880368b8950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0xfaa/0x13a0 fs/jbd2/transaction.c:444
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: c8 85 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 ba 1e 00 fb f4 bc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000242
RAX: 0000000000169051 RBX: ffffffff8e4975c0 RCX: ffffffff8b8ccc75
RDX: 0000000000000000 RSI: ffffffff8de7a16b RDI: ffffffff8c1aeb20
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1017086795
R10: ffff8880b8433cab R11: 0000000000000000 R12: fffffbfff1c92eb8
R13: 0000000000000000 R14: ffffffff90d98910 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124351000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558dce7cf528 CR3: 000000000e598000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x251/0x260 init/main.c:760
start_kernel+0x47f/0x480 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148