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:21504 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:2)
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
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_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
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_old_data_flush fs/fs-writeback.c:2345 [inline]
wb_do_writeback fs/fs-writeback.c:2398 [inline]
wb_workfn+0xb52/0xf60 fs/fs-writeback.c:2426
process_one_work kernel/workqueue.c:3288 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3371
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452
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
Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
#0: ffff88801aee3938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff88801aee3938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371
#1: ffffc90000117c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc90000117c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371
#2: ffff88803ec220d0 (&type->s_umount_key#84){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff88803e4081e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:3/48:
2 locks held by kworker/u8:4/67:
7 locks held by kworker/u8:8/1044:
3 locks held by kworker/u8:9/1115:
#0: ffff888032b0c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff888032b0c138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371
#1: ffffc900057afc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc900057afc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371
#2: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198
2 locks held by udevd/5163:
2 locks held by getty/5551:
#0: ffff888037aa50a0 (&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/0:5/5871:
#0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
#0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3371
#1: ffffc90004e67c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
#1: ffffc90004e67c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3371
#2: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
5 locks held by syz.2.60/6199:
2 locks held by udevd/6957:
#0: ffff888022671670 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff888022671670 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854
#1: ffff888022671840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#1: ffff888022671840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2554 [inline]
#1: ffff888022671840 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x931/0x1ea0 mm/filemap.c:2718
7 locks held by syz-executor/7754:
1 lock held by syz-executor/7784:
#0: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f15d578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107
1 lock held by syz.3.166/8020:
3 locks held by syz.9.265/8028:
1 lock held by dhcpcd/8026:
#0: ffff888040a788f8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#0: ffff888040a788f8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff888040a788f8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
4 locks held by dhcpcd-run-hook/8029:
=============================================
NMI backtrace for cpu 0
CPU: 0 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:
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
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8029 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:lockdep_hardirqs_off+0x2f/0xd0 kernel/locking/lockdep.c:4502
Code: 56 53 83 3d e2 37 46 04 00 0f 84 84 00 00 00 48 89 fb 65 8b 05 22 8c 2a 07 a9 00 00 f0 00 74 5c 83 3d 84 e0 35 0e 00 75 09 9c <58> a9 00 02 00 00 75 6a 65 8b 05 0a ce 2a 07 85 c0 74 56 65 4c 8b
RSP: 0018:ffffc90003ec71d8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8b27d48a RCX: 0000000000000046
RDX: 0000000000000100 RSI: ffffffff8d5c7b42 RDI: ffffffff8ba67a80
RBP: ffffc90003ec72d8 R08: ffffffff8216ab9d R09: ffff8880342b8718
R10: ffffc90003ec7580 R11: fffff520007d8eb2 R12: 1ffff920007d8e4d
R13: dffffc0000000000 R14: ffff8880342b86c0 R15: ffffc90003ec7260
FS: 00007f9bb5fadc80(0000) GS:ffff888126432000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9bb62117e8 CR3: 00000000299ba000 CR4: 00000000003526f0
Call Trace:
trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:130 [inline]
_raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:162
rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x157/0x400 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:45 [inline]
pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402
copy_pte_range mm/memory.c:1250 [inline]
copy_pmd_range+0x4ea/0x7c00 mm/memory.c:1405
copy_pud_range mm/memory.c:1442 [inline]
copy_p4d_range mm/memory.c:1466 [inline]
copy_page_range+0xaf4/0x1120 mm/memory.c:1552
dup_mmap+0xf4c/0x1d50 mm/mmap.c:1841
dup_mm kernel/fork.c:1531 [inline]
copy_mm+0x13b/0x4a0 kernel/fork.c:1583
copy_process+0x18be/0x3cd0 kernel/fork.c:2223
kernel_clone+0x249/0x840 kernel/fork.c:2653
__do_sys_clone kernel/fork.c:2794 [inline]
__se_sys_clone kernel/fork.c:2778 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778
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: 0033:0x7f9bb6147636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffdb8c3b210 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffdb8c3b218 RCX: 00007f9bb6147636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 000055810af85c30 R08: 0000000000000000 R09: 00000000000000d0
R10: 00007f9bb5fadf50 R11: 0000000000000246 R12: 000055810af93fc0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
EXT4-fs (loop9): error count since last fsck: 1
EXT4-fs (loop9): initial error at time 1776065778: ext4_free_branches:1023: inode 11
EXT4-fs (loop9): last error at time 1776065778: ext4_free_branches:1023: inode 11