INFO: task kworker/1:9:5933 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:9 state:D stack:27528 pid:5933 tgid:5933 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: xfs-sync/loop1 xfs_flush_inodes_worker
Call Trace:
context_switch kernel/sched/core.c:5290 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6902
__schedule_loop kernel/sched/core.c:6984 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6999
wb_wait_for_completion+0x360/0x680 fs/fs-writeback.c:226
sync_inodes_sb+0x1cb/0xba0 fs/fs-writeback.c:2922
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+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.1.2:5941 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2 state:D stack:21336 pid:5941 tgid:5939 ppid:5819 task_flags:0x400740 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5290 [inline]
__schedule+0x14db/0x5030 kernel/sched/core.c:6902
__schedule_loop kernel/sched/core.c:6984 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6999
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:1001
__kernel_write_iter+0x428/0x910 fs/read_write.c:621
dump_emit_page fs/coredump.c:1299 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1373
elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111
coredump_write+0x1121/0x18b0 fs/coredump.c:1050
do_coredump fs/coredump.c:1127 [inline]
vfs_coredump+0x332c/0x3e60 fs/coredump.c:1201
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+0x87/0x4e0 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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe01558f749
RSP: 002b:00007fe0164120e8 EFLAGS: 00000246
ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fe0157e5fa8 RCX: 00007fe01558f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe0157e5fac
RBP: 00007fe0157e5fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe0157e6038 R14: 00007ffed3865930 R15: 00007ffed3865a18
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e144ce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e144ce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e144ce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:7/1001:
2 locks held by getty/5577:
#0: ffff88814d5020a0 (&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
1 lock held by syz-executor/5818:
#0: ffffffff8e14a2f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e14a2f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:961
4 locks held by kworker/1:9/5933:
#0: ffff888028eb3948 ((wq_completion)xfs-sync/loop1){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc900046bfc40 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffff8880329800e0 (&type->s_umount_key#52){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:661
#3: ffff888142360820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#3: ffff888142360820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1af/0xba0 fs/fs-writeback.c:2920
2 locks held by syz.1.2/5941:
#0: ffff888032980420 (sb_writers#12){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline]
#0: ffff888032980420 (sb_writers#12){.+.+}-{0:0}, at: vfs_coredump+0x332c/0x3e60 fs/coredump.c:1201
#1: ffff88805887dd30 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: xfs_ilock+0xee/0x370 fs/xfs/xfs_inode.c:149
4 locks held by kworker/1:11/6368:
#0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000ba6fc40 (ser_release_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffffffff8f51be88 (rtnl_mutex){+.+.}-{4:4}, at: ser_release+0x107/0x240 drivers/net/caif/caif_serial.c:293
#3: ffffffff8e14a2f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#3: ffffffff8e14a2f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2b1/0x6e0 kernel/rcu/tree_exp.h:961
4 locks held by sed/7383:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 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: 1001 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-7:1)
RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline]
RIP: 0010:delay_tsc+0x71/0xc0 arch/x86/lib/delay.c:72
Code: 00 00 e8 a2 c9 33 f6 65 8b 05 eb 2b 45 07 85 c0 74 1c f3 90 bf 01 00 00 00 e8 eb c7 33 f6 e8 16 78 01 00 39 c5 75 0e 0f 01 f9 <66> 90 eb bd e8 a6 32 d6 f5 eb dd 4c 29 fb e8 fc 77 01 00 89 c5 0f
RSP: 0018:ffffc90003d3da50 EFLAGS: 00000046
RAX: 00000000c71367b4 RBX: 0000000000000899 RCX: 0000000000000001
RDX: 0000000000000079 RSI: ffffffff8be09740 RDI: ffffffff8be09700
RBP: 0000000000000001 R08: ffff888141708237 R09: 1ffff110282e1046
R10: dffffc0000000000 R11: ffffffff8b5d43f0 R12: 1ffffffff33c628a
R13: 00000000ffffffff R14: 00000079c713651c R15: 000000000000021a
FS: 0000000000000000(0000) GS:ffff888125cf9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6bc63a57e8 CR3: 000000007541a000 CR4: 00000000003526f0
Call Trace:
udelay include/asm-generic/delay.h:62 [inline]
wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:1967
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+0x1301/0x1b60 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3131 [inline]
console_flush_one_record kernel/printk/printk.c:3217 [inline]
console_flush_all+0x713/0xb00 kernel/printk/printk.c:3291
__console_flush_and_unlock kernel/printk/printk.c:3321 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3361
vprintk_emit+0x47b/0x550 kernel/printk/printk.c:2428
_printk+0xcf/0x120 kernel/printk/printk.c:2453
__xfs_printk fs/xfs/xfs_message.c:24 [inline]
xfs_printk_level+0x18b/0x280 fs/xfs/xfs_message.c:44
xfs_buf_verifier_error+0x1c0/0x2a0 fs/xfs/xfs_error.c:308
xfs_allocbt_read_verify+0x5f/0xe0 fs/xfs/libxfs/xfs_alloc_btree.c:-1
__xfs_buf_ioend+0x332/0x6d0 fs/xfs/xfs_buf.c:1174
xfs_buf_iowait+0x143/0x440 fs/xfs/xfs_buf.c:1381
_xfs_buf_read fs/xfs/xfs_buf.c:643 [inline]
xfs_buf_read_map+0x325/0xa30 fs/xfs/xfs_buf.c:709
xfs_trans_read_buf_map+0x1d7/0x8a0 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:212 [inline]
xfs_btree_read_buf_block+0x290/0x470 fs/xfs/libxfs/xfs_btree.c:1402
xfs_btree_lookup_get_block+0x28d/0x500 fs/xfs/libxfs/xfs_btree.c:1907
xfs_btree_lookup+0x4e1/0x1410 fs/xfs/libxfs/xfs_btree.c:2018
xfs_alloc_lookup fs/xfs/libxfs/xfs_alloc.c:166 [inline]
xfs_alloc_lookup_ge fs/xfs/libxfs/xfs_alloc.c:198 [inline]
xfs_alloc_cur_setup fs/xfs/libxfs/xfs_alloc.c:966 [inline]
xfs_alloc_ag_vextent_near+0x447/0x11d0 fs/xfs/libxfs/xfs_alloc.c:1705
xfs_alloc_vextent_near_bno+0x2e7/0x560 fs/xfs/libxfs/xfs_alloc.c:3962
xfs_bmap_btalloc_filestreams fs/xfs/libxfs/xfs_bmap.c:3566 [inline]
xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3661 [inline]
xfs_bmapi_allocate+0x1af7/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3938
xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4447 [inline]
xfs_bmapi_convert_delalloc+0x7e2/0x1430 fs/xfs/libxfs/xfs_bmap.c:4503
xfs_map_blocks fs/xfs/xfs_aops.c:445 [inline]
xfs_writeback_range+0x674/0xf30 fs/xfs/xfs_aops.c:489
iomap_writeback_range fs/iomap/buffered-io.c:1744 [inline]
iomap_writeback_folio+0x1408/0x23f0 fs/iomap/buffered-io.c:1862
iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1922
xfs_vm_writepages+0x296/0x310 fs/xfs/xfs_aops.c:701
do_writepages+0x32e/0x550 mm/page-writeback.c:2554
__writeback_single_inode+0x133/0x1070 fs/fs-writeback.c:1750
writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2041
wb_writeback+0x42b/0xaa0 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x3f9/0xed0 fs/fs-writeback.c:2414
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+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245