INFO: task kworker/1:7:6047 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:7 state:D stack:20840 pid:6047 tgid:6047 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: xfs-sync/loop5 xfs_flush_inodes_worker
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
wb_wait_for_completion+0x360/0x680 fs/fs-writeback.c:226
sync_inodes_sb+0x1c9/0xb40 fs/fs-writeback.c:2894
xfs_flush_inodes_worker+0x61/0x80 fs/xfs/xfs_super.c:662
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: task syz.5.1535:14915 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1535 state:D stack:20712 pid:14915 tgid:14914 ppid:11610 task_flags:0x400740 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
__flush_work+0x9b9/0xbc0 kernel/workqueue.c:4331
xfs_file_buffered_write+0x266/0x8a0 fs/xfs/xfs_file.c:1000
__kernel_write_iter+0x428/0x910 fs/read_write.c:619
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1372
elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
coredump_write+0x1121/0x18b0 fs/coredump.c:1049
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200
get_signal+0x1108/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 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+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f46dd98f749
RSP: 002b:00007f46dbbf60e8 EFLAGS: 00000246
ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f46ddbe5fa8 RCX: 00007f46dd98f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f46ddbe5fac
RBP: 00007f46ddbe5fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f46ddbe6038 R14: 00007fffed5d4320 R15: 00007fffed5d4408
Showing all locks held in the system:
1 lock held by rcu_exp_gp_kthr/18:
1 lock held by khungtaskd/31:
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:2/36:
#0: ffff88813fe29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc90000ac7b80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
2 locks held by kworker/u8:3/50:
#0: ffff88813fe29148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
2 locks held by kworker/u8:5/150:
#0:
ffff8880b863ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
3 locks held by kworker/u8:10/3481:
#0: ffff88803094d948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000c0efb80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
2 locks held by getty/5586:
#0: ffff88814cc720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:3/5841:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000436fb80 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2:
ffffffff8e144d00
(
rcu_state.barrier_mutex
){+.+.}-{4:4}
, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816
4 locks held by kworker/1:7/6047:
#0:
ffff88803459e948
(
(wq_completion)xfs-sync/loop5
){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc900052e7b80 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffff88807ab600e0 (&type->s_umount_key#81){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:661
#3: ffff888141f6c820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#3: ffff888141f6c820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1ad/0xb40 fs/fs-writeback.c:2892
5 locks held by kworker/u8:19/11289:
6 locks held by kworker/u8:21/12221:
#0: ffff88801baa7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc900033b7b80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f504e10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670
#3: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x6a/0x4b0 net/caif/caif_dev.c:528
#4: ffff8880293cd380 (&caifn->caifdevs.lock){+.+.}-{4:4}, at: caif_exit_net+0x7d/0x4b0 net/caif/caif_dev.c:529
#5: ffffffff8e144e38 (
rcu_state.exp_mutex
){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956
2 locks held by syz.5.1535/14915:
#0: ffff88807ab60420 (sb_writers#14){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
#0: ffff88807ab60420 (sb_writers#14){.+.+}-{0:0}, at: vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200
#1: ffff888055e3a8b0 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: xfs_ilock+0xee/0x370 fs/xfs/xfs_inode.c:149
1 lock held by syz-executor/16509:
#0: ffffffff8f512448
(rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
(rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
(rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
1 lock held by syz-executor/16582:
#0: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 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:363 [inline]
watchdog+0xe40/0xe90 kernel/hung_task.c:557
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12221 Comm: kworker/u8:21 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: netns cleanup_net
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 5f a5 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3c 08 0c fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc900033b7190 EFLAGS: 00000002
RAX: 0000000000000036 RBX: 0000000000000036 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888025420237 R09: 1ffff11004a84046
R10: dffffc0000000000 R11: ffffffff851c5830 R12: dffffc0000000000
R13: ffffffff99af09eb R14: ffffffff99e05380 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f189de89e9c CR3: 000000005ffba000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
_printk+0xcf/0x120 kernel/printk/printk.c:2451
ip_vs_est_kthread_destroy net/netfilter/ipvs/ip_vs_est.c:512 [inline]
ip_vs_stop_estimator+0xbb8/0xec0 net/netfilter/ipvs/ip_vs_est.c:587
ip_vs_control_net_cleanup_sysctl net/netfilter/ipvs/ip_vs_ctl.c:4400 [inline]
ip_vs_control_net_cleanup+0x269/0x3e0 net/netfilter/ipvs/ip_vs_ctl.c:4491
__ip_vs_cleanup_batch+0x8b/0x100 net/netfilter/ipvs/ip_vs_core.c:2350
ops_exit_list net/core/net_namespace.c:205 [inline]
ops_undo_list+0x525/0x990 net/core/net_namespace.c:252
cleanup_net+0x4d8/0x7a0 net/core/net_namespace.c:696
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246