INFO: task kworker/u4:12:6236 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:12 state:D stack:23376 pid:6236 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:6)
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1483 [inline]
__writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700
writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
wb_check_background_flush fs/fs-writeback.c:2177 [inline]
wb_do_writeback fs/fs-writeback.c:2265 [inline]
wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
INFO: task syz.6.524:8992 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.524 state:D stack:29128 pid:8992 ppid:7709 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write_nested+0x1b1/0x1f0 kernel/locking/rwsem.c:1690
inode_lock_nested include/linux/fs.h:839 [inline]
do_unlinkat+0x17c/0x570 fs/namei.c:4384
__do_sys_unlink fs/namei.c:4447 [inline]
__se_sys_unlink fs/namei.c:4445 [inline]
__x64_sys_unlink+0x49/0x50 fs/namei.c:4445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbba978f749
RSP: 002b:00007fbbaa5cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fbba99e6090 RCX: 00007fbba978f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007fbba9813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbba99e6128 R14: 00007fbba99e6090 R15: 00007ffd0e4b9a38
INFO: task syz.6.524:8994 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.524 state:D stack:28400 pid:8994 ppid:7709 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
inode_lock include/linux/fs.h:804 [inline]
open_last_lookups fs/namei.c:3561 [inline]
path_openat+0x7c6/0x3190 fs/namei.c:3794
do_filp_open+0x1c5/0x3d0 fs/namei.c:3824
do_sys_openat2+0x12c/0x1c0 fs/open.c:1421
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbba978f749
RSP: 002b:00007fbbaa5aa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbba99e6180 RCX: 00007fbba978f749
RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fbba9813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbba99e6218 R14: 00007fbba99e6180 R15: 00007ffd0e4b9a38
Showing all locks held in the system:
2 locks held by kworker/1:0/23:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900001d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900001d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by khungtaskd/28:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
1 lock held by syz-executor/6083:
4 locks held by kworker/u4:12/6236:
#0: ffff88801a27e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a27e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000371fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000371fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88805bc401c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108
3 locks held by kworker/u4:15/6417:
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90004327d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90004327d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286
2 locks held by getty/6954:
#0: ffff88803126a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90004a262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
3 locks held by kworker/1:11/8462:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000bf57d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000bf57d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
4 locks held by syz.6.524/8969:
2 locks held by syz.6.524/8992:
#0: ffff8880549de418 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff88805bc40590 (&type->i_mutex_dir_key#13/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#1: ffff88805bc40590 (&type->i_mutex_dir_key#13/1){+.+.}-{3:3}, at: do_unlinkat+0x17c/0x570 fs/namei.c:4384
2 locks held by syz.6.524/8994:
#0: ffff8880549de418 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff88805bc40590 (&type->i_mutex_dir_key#13){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff88805bc40590 (&type->i_mutex_dir_key#13){++++}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline]
#1: ffff88805bc40590 (&type->i_mutex_dir_key#13){++++}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794
2 locks held by syz.2.749/10286:
#0: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
#1: ffff88802181c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff88802181c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770
2 locks held by syz.2.749/10287:
#0: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
#1: ffff88802181c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff88802181c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770
2 locks held by syz.2.749/10288:
#0: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880549de0e0 (&type->s_umount_key#94){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
#1: ffff88802181c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff88802181c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2770
1 lock held by syz-executor/10461:
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511
4 locks held by syz-executor/10801:
#0: ffff888059aace70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
#0: ffff888059aace70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709
#1: ffff888059aac0b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5273
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline]
#2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540
#3: ffff8880262a5b38 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1763
2 locks held by syz.8.891/11006:
#0: ffffffff8dfa8610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516
#1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: bareudp_exit_batch_net+0xb4/0x1f0 drivers/net/bareudp.c:781
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2964 Comm: kworker/u4:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:409 [inline]
RIP: 0010:batadv_nc_worker+0x187/0x610 net/batman-adv/network-coding.c:719
Code: 14 03 00 00 48 c7 c2 20 5c c5 8b e8 c3 e8 37 f7 48 89 e8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 ef e8 3d 3b ad f7 48 8b 6d 00 <48> 85 ed 0f 94 c0 48 81 c5 38 fe ff ff 0f 94 c1 08 c1 74 07 e8 30
RSP: 0018:ffffc9000c0b7b60 EFLAGS: 00000246
RAX: 1ffff11009e8d8f0 RBX: 0000000000000001 RCX: ffff88802bce1e00
RDX: 0000000000000000 RSI: ffffffff8afc6f60 RDI: ffffffff8afc6f20
RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: dffffc0000000000
R13: ffffffff8a2fc2c2 R14: ffff88805de7cc80 R15: 00000000000000f0
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558fb5fcc138 CR3: 000000006898a000 CR4: 00000000003506e0
Call Trace:
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293