INFO: task syz.0.52:6227 blocked for more than 143 seconds. Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.52 state:D stack:28952 pid:6227 tgid:6196 ppid:5830 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] lock_rename fs/namei.c:3265 [inline] do_renameat2+0x3dd/0xc50 fs/namei.c:5216 __do_sys_renameat2 fs/namei.c:5304 [inline] __se_sys_renameat2 fs/namei.c:5301 [inline] __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5301 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: 0033:0x7f984e18e969 RSP: 002b:00007f984f000038 EFLAGS: 00000246 ORIG_RAX: 000000000000013c RAX: ffffffffffffffda RBX: 00007f984e3b6080 RCX: 00007f984e18e969 RDX: ffffffffffffff9c RSI: 0000200000000580 RDI: ffffffffffffff9c RBP: 00007f984e210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000005c0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f984e3b6080 R15: 00007fff5da96f48 INFO: task syz.0.52:6238 blocked for more than 144 seconds. Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.52 state:D stack:28952 pid:6238 tgid:6196 ppid:5830 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: 0033:0x7f984e18e969 RSP: 002b:00007f984efdf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f984e3b6160 RCX: 00007f984e18e969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000280 RBP: 00007f984e210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f984e3b6160 R15: 00007fff5da96f48 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: #0: ffff8881442c8948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8881442c8948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000127c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff88805c78a0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805d240cc8 (&inode->ei_update_lock){+.+.}-{4:4}, at: bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2171 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 getty/5573: #0: ffff88803488a0a0 (&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 udevd/6132: 1 lock held by syz-executor/6134: #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 5 locks held by syz.0.52/6197: #0: ffff88805c78a420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: open_last_lookups fs/namei.c:3797 [inline] #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4036 #2: ffff88805d240cc8 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:569 #3: ffff888070884228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888070884228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888070884228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385 #4: ffff8880708a6590 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68f/0x14c0 fs/bcachefs/btree_update_interior.c:1179 2 locks held by syz.0.52/6227: #0: ffff88805c78a420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3265 [inline] #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: do_renameat2+0x3dd/0xc50 fs/namei.c:5216 2 locks held by syz.0.52/6238: #0: ffff88805c78a420 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88805d2408e0 (&sb->s_type->i_mutex_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805d2408e0 (&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/6225: 2 locks held by syz-executor/7347: #0: ffff88802e4160e0 (&type->s_umount_key#58){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802e4160e0 (&type->s_umount_key#58){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802e4160e0 (&type->s_umount_key#58){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffffffff8df41200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774 3 locks held by dhcpcd-run-hook/8334: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #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: 6134 Comm: syz-executor Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:check_preemption_disabled+0x0/0x120 lib/smp_processor_id.c:13 Code: c7 40 fe c0 8b 48 c7 c6 80 fe c0 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 53 48 83 ec 10 65 48 8b 05 4e fe 22 07 48 89 44 24 RSP: 0018:ffffc90000a08b28 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffffffff821faabd RCX: 4e69a08322febf00 RDX: ffff888033f58878 RSI: ffffffff8d73725b RDI: ffffffff8bc0fea0 RBP: ffffc90000a08e30 R08: 0000000010c6f3ec R09: 0000000065238455 R10: 000000000000000a R11: ffffffff81ce9356 R12: 0000000000000000 R13: ffffffff81a88ce4 R14: ffff888064239e00 R15: 0000000000000286 FS: 0000555558bc2500(0000) GS:ffff8881261fd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f667db32018 CR3: 000000007c7cc000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_off+0x74/0x110 kernel/locking/lockdep.c:4512 trace_hardirqs_off+0x12/0x40 kernel/trace/trace_preemptirq.c:104 kasan_quarantine_put+0x3d/0x220 mm/kasan/quarantine.c:207 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free_after_rcu_debug+0x127/0x290 mm/slub.c:4692 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2824 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 31 f3 1e 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 20 f3 1e 00 eb 06 e8 19 f3 1e 00 fb 48 c7 c7 80 fa f2 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 f9 3f RSP: 0018:ffffc9000466f940 EFLAGS: 00000293 RAX: ffffffff81a0dc47 RBX: ffffffff81a0db04 RCX: ffff888064239e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df2fa80 RBP: ffffc9000466fa50 R08: ffffffff8f7daf77 R09: 1ffffffff1efb5ee R10: dffffc0000000000 R11: fffffbfff1efb5ef R12: dffffc0000000000 R13: 1ffff920008cdf2c R14: 0000000000000200 R15: 000000000000005a _printk+0xcf/0x120 kernel/printk/printk.c:2475 _btrfs_printk+0x562/0x5b0 fs/btrfs/messages.c:248 btrfs_put_super+0x69/0x80 fs/btrfs/super.c:73 generic_shutdown_super+0x132/0x2c0 fs/super.c:642 kill_anon_super+0x3b/0x70 fs/super.c:1237 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2099 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x9a/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: 0033:0x7fee1918fc97 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd1ff59298 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fee1921089d RCX: 00007fee1918fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd1ff59350 RBP: 00007ffd1ff59350 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd1ff5a3e0 R13: 00007fee1921089d R14: 00000000000408be R15: 00007ffd1ff5a420