INFO: task syz.5.391:9811 blocked for more than 143 seconds.
Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.391 state:D stack:28952 pid:9811 tgid:9752 ppid:9078 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_sys_chdir fs/open.c:557 [inline]
__se_sys_chdir+0x91/0x280 fs/open.c:551
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: 0033:0x7ff99cd8e969
RSP: 002b:00007ff99dc23038 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 00007ff99cfb6080 RCX: 00007ff99cd8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000000c0
RBP: 00007ff99ce10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff99cfb6080 R15: 00007ffce37d04f8
INFO: task syz.5.391:9813 blocked for more than 144 seconds.
Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.391 state:D stack:28952 pid:9813 tgid:9752 ppid:9078 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_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694
inode_lock_nested include/linux/fs.h:902 [inline]
do_unlinkat+0x1bf/0x560 fs/namei.c:4630
__do_sys_unlinkat fs/namei.c:4684 [inline]
__se_sys_unlinkat fs/namei.c:4677 [inline]
__x64_sys_unlinkat+0xd3/0xf0 fs/namei.c:4677
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: 0033:0x7ff99cd8e969
RSP: 002b:00007ff99dc02038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007ff99cfb6160 RCX: 00007ff99cd8e969
RDX: 0000000000000000 RSI: 0000200000000c40 RDI: ffffffffffffff9c
RBP: 00007ff99ce10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007ff99cfb6160 R15: 00007ffce37d04f8
Showing all locks held in the system:
6 locks held by kworker/u8:1/13:
#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: ffffc90000127c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000127c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2d4050 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608
#3: ffff88806adaf0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#3: ffff88806adaf0e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff88806adaf0e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506
#4: ffff88805f148250 (&devlink->lock_key#20){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff88805f148250 (&devlink->lock_key#20){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff88805f148250 (&devlink->lock_key#20){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506
#5: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
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:
2 locks held by getty/5578:
#0: ffff8880351320a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/u8:11/8520:
#0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
#1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
#2: ffff8880b8925558 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1046 [inline]
#2: ffff8880b8925558 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1127
5 locks held by syz.5.391/9755:
#0: ffff888023db8420 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff88805ef4dc68 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
#1: ffff88805ef4dc68 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4132
#2: ffff88805ef4e050 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:550
#3: ffff888042004228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#3: ffff888042004228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#3: ffff888042004228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3382
#4: ffff888042026590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179
1 lock held by syz.5.391/9811:
#0: ffff88805ef4dc68 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline]
#0: ffff88805ef4dc68 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833
2 locks held by syz.5.391/9813:
#0: ffff888023db8420 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff88805ef4dc68 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline]
#1: ffff88805ef4dc68 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: do_unlinkat+0x1bf/0x560 fs/namei.c:4630
2 locks held by bch-copygc/loop/9806:
1 lock held by syz-executor/11003:
#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
7 locks held by syz-executor/11673:
#0: ffff8880354de420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
#0: ffff8880354de420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680
#1: ffff888021f37488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325
#2: ffff8880266da968 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326
#3: ffffffff8eb81ca8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216
#4: ffff88806124d0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff88806124d0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
#4: ffff88806124d0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1293
#5: ffff88806124e250 (&devlink->lock_key#15){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675
#6: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xdb/0x670 drivers/net/netdevsim/netdev.c:1059
1 lock held by syz-executor/12044:
#0: ffffffff8f2e0b88 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37a/0x1d90 drivers/net/tun.c:3038
2 locks held by dhcpcd/12095:
#0: ffff888022894a08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#0: ffff888022894a08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline]
#0: ffff888022894a08 (&sb->s_type->i_mutex_key#9){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391
#1: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#1: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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: 9806 Comm: bch-copygc/loop Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
RIP: 0010:do_raw_spin_lock+0x6d/0x290 kernel/locking/spinlock_debug.c:115
Code: 28 97 be 87 8d 48 c7 44 24 30 e0 ae 9e 81 48 8d 4c 24 20 48 c1 e9 03 48 b8 f1 f1 f1 f1 04 f3 f3 f3 48 89 4c 24 18 4a 89 04 39 <4c> 8d 77 04 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 9f 01
RSP: 0018:ffffc90003aff1c0 EFLAGS: 00000a06
RAX: f3f3f304f1f1f1f1 RBX: ffff88804204a658 RCX: 1ffff9200075fe3c
RDX: 0000000000000000 RSI: ffffffff8d91eb0b RDI: ffff88804204a658
RBP: ffffc90003aff278 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff843c6ff6 R12: ffff88804204a658
R13: ffff8880420495c0 R14: ffff88803a400000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126103000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d2f1fcb680 CR3: 000000000dd36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_lock include/linux/spinlock.h:351 [inline]
bch2_journal_pin_drop+0x36/0x420 fs/bcachefs/journal_reclaim.c:381
bch2_btree_write_buffer_flush_locked+0x35f9/0x45a0 fs/bcachefs/btree_write_buffer.c:494
bch2_btree_write_buffer_flush_nocheck_rw fs/bcachefs/btree_write_buffer.c:621 [inline]
bch2_btree_write_buffer_tryflush+0x150/0x1a0 fs/bcachefs/btree_write_buffer.c:635
bch2_copygc_get_buckets fs/bcachefs/movinggc.c:160 [inline]
bch2_copygc+0x28a/0x3cf0 fs/bcachefs/movinggc.c:221
bch2_copygc_thread+0x67f/0xb10 fs/bcachefs/movinggc.c:398
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