INFO: task syz.1.52:6268 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.52 state:D stack:19816 pid:6268 tgid:6210 ppid:5822 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 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 fdget_pos+0x247/0x320 fs/file.c:1213 class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_write+0x79/0x250 fs/read_write.c:727 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: 0033:0x7fc71a58e969 RSP: 002b:00007fc71b44a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc71a7b6080 RCX: 00007fc71a58e969 RDX: 0000000000000002 RSI: 0000200000000300 RDI: 0000000000000004 RBP: 00007fc71a610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc71a7b6080 R15: 00007fff89584798 INFO: task syz.1.52:6269 blocked for more than 144 seconds. Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.52 state:D stack:26424 pid:6269 tgid:6210 ppid:5822 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+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:867 [inline] bch2_write_iter+0x139/0x2b90 fs/bcachefs/fs-io-buffered.c:1076 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 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: 0033:0x7fc71a58e969 RSP: 002b:00007fc71b429038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc71a7b6160 RCX: 00007fc71a58e969 RDX: 0000000000000002 RSI: 0000200000000300 RDI: 0000000000000004 RBP: 00007fc71a610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc71a7b6160 R15: 00007fff89584798 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/0:1H/44: #0: ffff8880b88399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8823b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 3 locks held by kworker/1:1/49: 1 lock held by udevd/5188: 2 locks held by getty/5580: #0: ffff88802fc950a0 (&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/5830: 2 locks held by udevd/5832: 5 locks held by syz.1.52/6211: #0: ffff88805762c420 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88804e0d88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88804e0d88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: do_truncate+0x186/0x220 fs/open.c:63 #2: ffff888054300a70 (&c->snapshot_create_lock){.+.+}-{4:4}, at: bch2_truncate+0xeb/0x200 fs/bcachefs/io_misc.c:295 #3: ffff888054304228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888054304228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888054304228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3208 #4: ffff888054326590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 1 lock held by syz.1.52/6268: #0: ffff8880313130b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 3 locks held by syz.1.52/6269: #0: ffff8880313130b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff88805762c420 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #1: ffff88805762c420 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #2: ffff88804e0d88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #2: ffff88804e0d88e0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: bch2_write_iter+0x139/0x2b90 fs/bcachefs/fs-io-buffered.c:1076 3 locks held by bch-copygc/loop/6266: 2 locks held by syz-executor/6455: #0: ffff88807fd9c0e0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807fd9c0e0 (&type->s_umount_key#73){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807fd9c0e0 (&type->s_umount_key#73){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8df43680 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #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: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: 6266 Comm: bch-copygc/loop Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lockdep_rht_mutex_is_held+0x19/0x90 lib/rhashtable.c:49 Code: cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 48 89 fb e8 02 dd 0e fd 48 c7 c0 50 02 7e 8f 48 c1 e8 03 <48> b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 40 8b 2d 2f ee RSP: 0018:ffffc9000e89ede8 EFLAGS: 00000a02 RAX: 1ffffffff1efc04a RBX: ffff888054304260 RCX: ffff888026100000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888054304260 RBP: ffffc9000e89ef68 R08: 0001000000000000 R09: 00c800ac00180000 R10: 0000000000000000 R11: ffffffff841d3d66 R12: ffff888060bf4800 R13: dffffc0000000000 R14: ffffc9000e89f000 R15: ffff888054304260 FS: 0000000000000000(0000) GS:ffff8881260f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555594c9b608 CR3: 0000000063ae4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __rhashtable_lookup include/linux/rhashtable.h:602 [inline] rhashtable_lookup+0x14e/0x800 include/linux/rhashtable.h:646 rhashtable_lookup_fast include/linux/rhashtable.h:672 [inline] bch2_btree_key_cache_find+0x1a9/0x2a0 fs/bcachefs/btree_key_cache.c:60 btree_path_traverse_cached_fast fs/bcachefs/btree_key_cache.c:352 [inline] bch2_btree_path_traverse_cached+0x17d/0xaa0 fs/bcachefs/btree_key_cache.c:385 bch2_btree_path_traverse_one+0x400/0x2430 fs/bcachefs/btree_iter.c:1165 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:248 [inline] bch2_btree_iter_peek_slot+0x760/0x1ec0 fs/bcachefs/btree_iter.c:2769 __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