INFO: task syz.3.36:6143 blocked for more than 143 seconds. Not tainted 6.15.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.36 state:D stack:26184 pid:6143 tgid:6089 ppid:5818 task_flags:0x400140 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: 0033:0x7fea4e58e969 RSP: 002b:00007fea4f478038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fea4e7b6080 RCX: 00007fea4e58e969 RDX: 0000200000000140 RSI: 0000200000000080 RDI: 0000200000000040 RBP: 00007fea4e610ab1 R08: 0000200000000180 R09: 0000000000000000 R10: 0000000000200000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fea4e7b6080 R15: 00007ffd5dd91c08 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: 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 6 locks held by dhcpcd/5480: #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: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #3: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_change+0xe5/0x250 kernel/sched/psi.c:912 #4: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: page_table_check_set+0x16b/0x710 mm/page_table_check.c:112 #5: ffff888032dd6428 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] #5: ffff888032dd6428 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x6e/0x1290 kernel/sched/core.c:4212 2 locks held by getty/5569: #0: ffff888030a680a0 (&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 1 lock held by syz-executor/5813: 5 locks held by syz.3.36/6090: #0: ffff88805baaa420 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff888077cc88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff888077cc88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff888077cc88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 #2: ffff888077cc8cc8 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569 #3: ffff888054a84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888054a84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888054a84228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3202 #4: ffff888054aa6590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 1 lock held by syz.3.36/6143: #0: ffff888077cc88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline] #0: ffff888077cc88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 1 lock held by bch-copygc/loop/6131: 1 lock held by syz-executor/6627: #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 dhcpcd-run-hook/8713: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller #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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6131 Comm: bch-copygc/loop Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:lock_is_held_type+0x51/0x190 kernel/locking/lockdep.c:5931 Code: c3 2e 04 00 0f 84 fe 00 00 00 65 8b 05 a8 51 23 07 85 c0 0f 85 ef 00 00 00 65 4c 8b 2c 25 08 30 72 92 41 83 bd ec 0a 00 00 00 <0f> 85 d8 00 00 00 89 f5 49 89 fe 48 c7 04 24 00 00 00 00 9c 8f 04 RSP: 0018:ffffc9000baef618 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0772629f63ea8600 RDX: ffff88802ac35a00 RSI: 00000000ffffffff RDI: ffffffff8df3b860 RBP: ffffc9000baefa30 R08: 0000000000000000 R09: 00000000deadbf07 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88802ac35a00 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881261fd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9494464b10 CR3: 000000007be66000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rht_ptr_rcu include/linux/rhashtable.h:376 [inline] __rhashtable_lookup include/linux/rhashtable.h:607 [inline] rhashtable_lookup include/linux/rhashtable.h:646 [inline] rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] bucket_in_flight fs/bcachefs/movinggc.c:143 [inline] bch2_copygc_get_buckets fs/bcachefs/movinggc.c:169 [inline] bch2_copygc+0x1216/0x3cf0 fs/bcachefs/movinggc.c:221 bch2_copygc_thread+0x8c9/0xd40 fs/bcachefs/movinggc.c:405 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