INFO: task syz.4.59:6381 blocked for more than 143 seconds.
Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.59 state:D stack:28952 pid:6381 tgid:6325 ppid:5827 task_flags:0x400040 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084
__down_read_common kernel/locking/rwsem.c:1248 [inline]
__down_read kernel/locking/rwsem.c:1261 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526
inode_lock_shared include/linux/fs.h:877 [inline]
lookup_slow+0x46/0x70 fs/namei.c:1833
walk_component+0x2d2/0x400 fs/namei.c:2138
lookup_last fs/namei.c:2636 [inline]
path_lookupat+0x163/0x430 fs/namei.c:2660
filename_lookup+0x212/0x570 fs/namei.c:2689
user_path_at+0x3a/0x60 fs/namei.c:3120
do_mount fs/namespace.c:4221 [inline]
__do_sys_mount fs/namespace.c:4435 [inline]
__se_sys_mount+0x2d3/0x410 fs/namespace.c:4412
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc9638e969
RSP: 002b:00007fdc97118038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fdc965b6160 RCX: 00007fdc9638e969
RDX: 0000200000000140 RSI: 0000200000000080 RDI: 0000200000000040
RBP: 00007fdc96410ab1 R08: 0000200000000180 R09: 0000000000000000
R10: 0000000000200000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdc965b6160 R15: 00007ffe1506cf98
Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
#0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000117c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000117c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2d5a50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
#3: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: mpls_net_exit+0x79/0x270 net/mpls/af_mpls.c:2706
4 locks held by kworker/u8:1/13:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000127c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000127c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
#3: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#3: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
2 locks held by dhcpcd/5486:
#0: ffff888060a256d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2388
#1: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6823
2 locks held by getty/5574:
#0: ffff888030a350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by syz.4.59/6326:
#0: ffff88805c46e420 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff8880548b9810 (&sb->s_type->i_mutex_key#28){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff8880548b9810 (&sb->s_type->i_mutex_key#28){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline]
#1: ffff8880548b9810 (&sb->s_type->i_mutex_key#28){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036
#2: ffff8880548b9bf8 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569
#3: ffff88805c384228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#3: ffff88805c384228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#3: ffff88805c384228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385
#4: ffff88805c3a6590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179
1 lock held by syz.4.59/6381:
#0: ffff8880548b9810 (&sb->s_type->i_mutex_key#28){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline]
#0: ffff8880548b9810 (&sb->s_type->i_mutex_key#28){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833
1 lock held by syz-executor/8672:
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998
2 locks held by syz-executor/8759:
#0: ffffffff8f2d5a50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x317/0x590 net/core/net_namespace.c:514
#1: ffffffff8f2e2588 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1160
3 locks held by syz.3.334/8766:
#0: ffff88807e358d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
#0: ffff88807e358d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678
#1: ffff88807e358078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213
#2: ffffffff8f448788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2064 [inline]
#2: ffffffff8f448788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2534
4 locks held by syz.5.338/8782:
#0: ffff888032aa8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
#0: ffff888032aa8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678
#1: ffff888032aa8078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213
#2: ffffffff8f448788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2064 [inline]
#2: ffffffff8f448788 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2534
#3: ffff88805b511b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1761
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
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:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8672 Comm: syz-executor Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:lock_acquire+0x70/0x360 kernel/locking/lockdep.c:5831
Code: f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 b8 a2 df 0d 73 16 e8 e1 d9 08 00 84 c0 75 0d f6 05 6a a0 c9 0d 01 0f 84 d7 01 00 00 <83> 3d 79 d1 df 0d 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c
RSP: 0018:ffffc9000452f808 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: dec5dd1a65dd3f00
RDX: 0000000000000000 RSI: ffffffff8bc0fe80 RDI: ffffffff8bc0fe40
RBP: ffffffff8238b391 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8238dcc9 R12: 0000000000000000
R13: ffffffff8dc16850 R14: 0000000000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881260ff000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f12baf18000 CR3: 000000000dd36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
write_seqlock include/linux/seqlock.h:876 [inline]
lock_mount_hash+0x11/0x40 fs/namespace.c:253
mntput_no_expire+0x282/0x860 fs/namespace.c:1476
mntput fs/namespace.c:1531 [inline]
namespace_unlock+0x5f2/0x670 fs/namespace.c:1824
drop_collected_mounts fs/namespace.c:2427 [inline]
put_mnt_ns+0xdf/0x130 fs/namespace.c:6245
free_nsproxy+0x4d/0x3c0 kernel/nsproxy.c:193
do_exit+0x8d1/0x2550 kernel/exit.c:952
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218
do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9d01f907fc
Code: Unable to access opcode bytes at 0x7f9d01f907d2.
RSP: 002b:00007ffd0b0ab5f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 000000000000006c RBX: 00007f9d02ce4620 RCX: 00007f9d01f907fc
RDX: 000000000000006c RSI: 00007f9d02ce4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd0b0ab644 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f9d02ce4670 R15: 0000000000000000