INFO: task syz.0.1201:12084 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1201 state:D stack:20056 pid:12084 tgid:12084 ppid:10693 task_flags:0x40064c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2873
sync_filesystem+0x17a/0x230 fs/sync.c:64
generic_shutdown_super+0x6f/0x2c0 fs/super.c:621
kill_block_super+0x44/0x90 fs/super.c:1722
xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2294
deactivate_locked_super+0xbc/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73
exc_page_fault+0xab/0x100 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f28a924f987
RSP: 002b:00007f28aa212120 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f28a938efc9
RDX: 00007f28aa212140 RSI: 00007f28aa212270 RDI: 000000000000000b
RBP: 00007f28a9411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f28a95e6038 R14: 00007f28a95e5fa0 R15: 00007ffc03ba42f8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3d620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5583:
#0: ffff88814d7090a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
6 locks held by kworker/u9:5/5839:
#0: ffff888060a77948
((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90003127ba0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90003127ba0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2:
ffff888050b7cdc8
(&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331
#3: ffff888050b7c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30 net/bluetooth/hci_sync.c:5684
#4: ffffffff8f435968 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2104 [inline]
#4: ffffffff8f435968 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x310 net/bluetooth/hci_conn.c:1319
#5: ffff888029191b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762
9 locks held by kworker/u8:15/9017:
2 locks held by syz.0.1201/12084:
#0: ffff888031ae80e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff888031ae80e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff888031ae80e0 (&type->s_umount_key#69){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
#1: ffff8880243e6820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880243e6820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2871
1 lock held by syz-executor/12448:
#0:
ffffffff8df430b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
ffffffff8df430b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by dhcpcd/13783:
#0: ffff88804c055288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#0: ffff88804c055288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff88804c055288 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
1 lock held by dhcpcd/13784:
#0: ffff88804b616988 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#0: ffff88804b616988 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff88804b616988 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
1 lock held by dhcpcd/13785:
#0: ffff88806a0de260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1679 [inline]
#0: ffff88806a0de260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3197
1 lock held by dhcpcd/13786:
#0: ffff88804b613b88
(&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
(&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
(&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
1 lock held by dhcpcd/13787:
#0: ffff888029446260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1679 [inline]
#0: ffff888029446260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcd0 net/packet/af_packet.c:3197
1 lock held by dhcpcd/13788:
#0: ffff88804b610208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#0: ffff88804b610208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff88804b610208 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
1 lock held by sed/13798:
=============================================
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 10/02/2025
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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 9017 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 32 ab 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 2c e7 10 fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 62 6c fb fb cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc900044bda90 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888023c98237 R09: 1ffff11004793046
R10: dffffc0000000000 R11: ffffffff8514d420 R12: dffffc0000000000
R13: ffffffff997d7901 R14: ffffffff99aeaf20 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812623d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555a3149a028 CR3: 0000000059b14000 CR4: 0000000000350ef0
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:3111 [inline]
console_flush_all+0x6f3/0xb10 kernel/printk/printk.c:3199
__console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3298
vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
_printk+0xcf/0x120 kernel/printk/printk.c:2448
print_hex_dump+0x1a8/0x260 lib/hexdump.c:285
xfs_hex_dump+0x3d/0x50 fs/xfs/xfs_message.c:110
xfs_buf_verifier_error+0x1cc/0x2a0 fs/xfs/xfs_error.c:310
xfs_agf_read_verify+0x16e/0x1f0 fs/xfs/libxfs/xfs_alloc.c:-1
__xfs_buf_ioend+0x342/0x6f0 fs/xfs/xfs_buf.c:1174
xfs_buf_iowait+0x167/0x480 fs/xfs/xfs_buf.c:1381
_xfs_buf_read fs/xfs/xfs_buf.c:643 [inline]
xfs_buf_read_map+0x335/0xa50 fs/xfs/xfs_buf.c:709
xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [inline]
xfs_read_agf+0x281/0x5c0 fs/xfs/libxfs/xfs_alloc.c:3376
xfs_alloc_read_agf+0x17c/0xb70 fs/xfs/libxfs/xfs_alloc.c:3411
xfs_bmap_longest_free_extent+0x77/0x150 fs/xfs/libxfs/xfs_bmap.c:3158
xfs_filestream_pick_ag fs/xfs/xfs_filestream.c:81 [inline]
xfs_filestream_create_association fs/xfs/xfs_filestream.c:297 [inline]
xfs_filestream_select_ag+0x81b/0x1b00 fs/xfs/xfs_filestream.c:360
xfs_bmap_btalloc_filestreams fs/xfs/libxfs/xfs_bmap.c:3544 [inline]
xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3661 [inline]
xfs_bmapi_allocate+0x1651/0x2e00 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+0x674/0xf70 fs/xfs/xfs_aops.c:489
iomap_writeback_range fs/iomap/buffered-io.c:1593 [inline]
iomap_writeback_folio+0xe75/0x1c80 fs/iomap/buffered-io.c:1718
iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1770
xfs_vm_writepages+0x296/0x310 fs/xfs/xfs_aops.c:701
do_writepages+0x32e/0x550 mm/page-writeback.c:2604
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195
wb_do_writeback fs/fs-writeback.c:2342 [inline]
wb_workfn+0x409/0xef0 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245