INFO: task syz.6.132:7366 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.132 state:D stack:27496 pid:7366 tgid:7322 ppid:6047 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_unlink fs/namei.c:4689 [inline] __se_sys_unlink fs/namei.c:4687 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4687 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: 0033:0x7f0fa7f8e969 RSP: 002b:00007f0fa8e39038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f0fa81b6080 RCX: 00007f0fa7f8e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000 RBP: 00007f0fa8010ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0fa81b6080 R15: 00007ffc98c45e48 INFO: task syz.6.132:7369 blocked for more than 144 seconds. Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.132 state:D stack:28952 pid:7369 tgid:7322 ppid:6047 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: 0033:0x7f0fa7f8e969 RSP: 002b:00007f0fa8df7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f0fa81b6240 RCX: 00007f0fa7f8e969 RDX: 0000200000000140 RSI: 0000200000000080 RDI: 0000200000000040 RBP: 00007f0fa8010ab1 R08: 0000200000000180 R09: 0000000000000000 R10: 0000000000200000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f0fa81b6240 R15: 00007ffc98c45e48 Showing all locks held in the system: 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 3 locks held by kworker/u8:4/63: 3 locks held by kworker/u8:5/1134: 1 lock held by udevd/5188: 2 locks held by getty/5568: #0: ffff88803481a0a0 (&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.6.132/7323: #0: ffff888052ef6420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 #2: ffff88807bebd120 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569 #3: ffff888048504228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888048504228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888048504228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385 #4: ffff888048526590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by syz.6.132/7366: #0: ffff888052ef6420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23/1){+.+.}-{4:4}, at: do_unlinkat+0x1bf/0x560 fs/namei.c:4630 1 lock held by syz.6.132/7369: #0: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:877 [inline] #0: ffff88807bebcd38 (&sb->s_type->i_mutex_key#23){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833 2 locks held by bch-copygc/loop/7361: 1 lock held by syz-executor/7650: #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 3 locks held by dhcpcd-run-hook/9768: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #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: 7361 Comm: bch-copygc/loop Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320 Code: 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 00 72 92 65 8b 15 d8 3b RSP: 0018:ffffc90002ef7150 EFLAGS: 00000293 RAX: ffffffff841889dd RBX: ffff88804a45c2f0 RCX: 0000000000000000 RDX: ffff888061333c00 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 1ffff1100948b861 R08: ffffc90002ef7027 R09: 0000000000000000 R10: ffffc90002ef7000 R11: fffff520005dee05 R12: 0000000000000064 R13: 0000000000000038 R14: 0000000000000000 R15: ffff88804a45c308 FS: 0000000000000000(0000) GS:ffff888126100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff3e170088 CR3: 000000005518e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bch2_btree_path_verify+0xea/0x310 fs/bcachefs/btree_iter.c:225 bch2_btree_path_traverse_one+0x1b4f/0x2430 fs/bcachefs/btree_iter.c:1224 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:248 [inline] bch2_btree_iter_peek_slot+0x772/0x1f00 fs/bcachefs/btree_iter.c:2763 __bch2_bkey_get_iter fs/bcachefs/btree_iter.h:591 [inline] bch2_bkey_get_iter fs/bcachefs/btree_iter.h:605 [inline] bch2_bucket_is_movable fs/bcachefs/movinggc.c:82 [inline] bch2_copygc_get_buckets fs/bcachefs/movinggc.c:169 [inline] bch2_copygc+0x9e4/0x3cf0 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