INFO: task syz-executor:9038 blocked for more than 143 seconds.
Not tainted 6.16.0-rc4-syzkaller-00308-ga79a588fc176 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:18792 pid:9038 tgid:9038 ppid:1 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
__writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2747
sync_filesystem+0xa3/0x230 fs/sync.c:54
generic_shutdown_super+0x6f/0x2c0 fs/super.c:622
bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618
deactivate_locked_super+0xb9/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f421cd8fc57
RSP: 002b:00007ffd0b4a3bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f421ce10925 RCX: 00007f421cd8fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd0b4a3c80
RBP: 00007ffd0b4a3c80 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd0b4a4d10
R13: 00007f421ce10925 R14: 0000000000073bf0 R15: 00007ffd0b4a4d50
Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
#0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:5/1015:
#0: ffff88801ee92148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801ee92148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000379fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000379fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
1 lock held by dhcpcd/5500:
#0: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1121
2 locks held by getty/5597:
#0: ffff88814c7470a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/u8:7/5947:
#0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc90004e47bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90004e47bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f4fe150 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
#3: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:174 [inline]
#3: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:249
#4: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#4: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
3 locks held by kworker/0:6/6002:
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000b117bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000b117bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
3 locks held by kworker/u8:8/8360:
#0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000b0dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000b0dfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by syz-executor/9038:
#0: ffff88807a5120e0 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88807a5120e0 (&type->s_umount_key#75){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88807a5120e0 (&type->s_umount_key#75){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
2 locks held by syz-executor/14372:
#0: ffffffff8f4fe150 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:570
#1: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
#1: ffffffff8f50ad48 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11218
1 lock held by syz.4.948/14431:
5 locks held by syz.4.948/14442:
#0: ffff888025ef8ef8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1217
#1: ffff88803a996428 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline]
#1: ffff88803a996428 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682
#2: ffff88805727d870 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
#2: ffff88805727d870 (&sb->s_type->i_mutex_key#21){+.+.}-{4:4}, at: generic_file_write_iter+0xe3/0x540 mm/filemap.c:4252
#3: ffff88805727d430 (&jfs_ip->rdwrlock#3){++++}-{4:4}, at: jfs_get_block+0x141/0xab0 fs/jfs/inode.c:213
#4: ffff88805727d4c0 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: extAlloc+0x13c/0xfb0 fs/jfs/jfs_extent.c:86
2 locks held by udevadm/14458:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00308-ga79a588fc176 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 14458 Comm: udevadm Not tainted 6.16.0-rc4-syzkaller-00308-ga79a588fc176 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:kasan_check_byte include/linux/kasan.h:399 [inline]
RIP: 0010:lock_acquire+0x85/0x360 kernel/locking/lockdep.c:5845
Code: 41 f1 08 00 84 c0 75 0d f6 05 3e 77 ec 0d 01 0f 84 d7 01 00 00 83 3d 19 be 02 0e 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 <4c> 89 ef e8 33 5a 83 00 83 3d fc bd 02 0e 00 0f 84 fa 00 00 00 65
RSP: 0018:ffffc9000b227730 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: af99c0889507a500
RDX: 0000000000000000 RSI: ffffffff825b5118 RDI: ffffffff8be1c2a0
RBP: ffffffff825b50fc R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100365f925 R12: 0000000000000002
R13: ffffffff8e13ee20 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fa1e2482880(0000) GS:ffff888125d50000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2cf1fffc CR3: 000000004d12c000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75
kernfs_active fs/kernfs/dir.c:39 [inline]
kernfs_dop_revalidate+0xd5/0x5d0 fs/kernfs/dir.c:1183
d_revalidate fs/namei.c:929 [inline]
lookup_fast+0x253/0x5b0 fs/namei.c:-1
walk_component fs/namei.c:2134 [inline]
link_path_walk+0x642/0xea0 fs/namei.c:2506
path_openat+0x28c/0x3830 fs/namei.c:4051
do_filp_open+0x1fa/0x410 fs/namei.c:4082
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1e1ca7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd04642150 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa1e2482880 RCX: 00007fa1e1ca7407
RDX: 0000000000080000 RSI: 00007ffd046422d0 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055c0bdd50ee0
R13: 000055c0bdd50ee0 R14: 0000000000000001 R15: 000055c0d0c32e60