INFO: task syz.3.4:5360 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-08836-gf8eb5bd9a818 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4 state:D stack:25744 pid:5360 tgid:5309 ppid:5228 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6674 __schedule_loop kernel/sched/core.c:6751 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6766 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6823 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1d7/0x220 kernel/locking/rwsem.c:1580 inode_lock include/linux/fs.h:815 [inline] do_truncate fs/open.c:63 [inline] do_ftruncate+0x44e/0x580 fs/open.c:181 do_sys_ftruncate fs/open.c:199 [inline] __do_sys_ftruncate fs/open.c:207 [inline] __se_sys_ftruncate fs/open.c:205 [inline] __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdf3ed7def9 RSP: 002b:00007fdf3fae2038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007fdf3ef36058 RCX: 00007fdf3ed7def9 RDX: 0000000000000000 RSI: 0000000000002ff8 RDI: 0000000000000004 RBP: 00007fdf3edf0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fdf3ef36058 R15: 00007ffe27d86178 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 2 locks held by kworker/u8:3/52: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000bc7d00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bc7d00 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 2 locks held by kworker/u8:8/2548: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90008e47d00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90008e47d00 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 2 locks held by getty/4985: #0: ffff888032a5a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 5 locks held by syz.3.4/5311: #0: ffff88807a5aa420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff888059088148 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #1: ffff888059088148 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: do_truncate+0x20c/0x310 fs/open.c:63 #2: ffff88805cb80a18 (&c->snapshot_create_lock){.+.+}-{3:3}, at: bch2_truncate+0x16c/0x2c0 fs/bcachefs/io_misc.c:290 #3: ffff88805cb842c0 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:151 [inline] #3: ffff88805cb842c0 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:250 [inline] #3: ffff88805cb842c0 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7de/0xd20 fs/bcachefs/btree_iter.c:3200 #4: ffff88805cba6690 (&c->gc_lock){.+.+}-{3:3}, at: bch2_btree_update_start+0x682/0x14e0 fs/bcachefs/btree_update_interior.c:1197 2 locks held by syz.3.4/5360: #0: ffff88807a5aa420 (sb_writers#17){.+.+}-{0:0}, at: do_ftruncate+0x28b/0x580 fs/open.c:178 #1: ffff888059088148 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline] #1: ffff888059088148 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: do_truncate fs/open.c:63 [inline] #1: ffff888059088148 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: do_ftruncate+0x44e/0x580 fs/open.c:181 1 lock held by bch-reclaim/loo/5327: 4 locks held by syz-executor/6013: 1 lock held by syz.0.134/6535: #0: ffffffff8e7e2308 (wq_pool_mutex){+.+.}-{3:3}, at: apply_wqattrs_lock kernel/workqueue.c:5152 [inline] #0: ffffffff8e7e2308 (wq_pool_mutex){+.+.}-{3:3}, at: __alloc_workqueue+0xa55/0x1f20 kernel/workqueue.c:5706 1 lock held by syz.2.115/6542: 2 locks held by syz.1.138/6549: #0: ffff888021f440e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x221/0x9d0 fs/super.c:344 #1: ffffffff8e7e2308 (wq_pool_mutex){+.+.}-{3:3}, at: apply_wqattrs_lock kernel/workqueue.c:5152 [inline] #1: ffffffff8e7e2308 (wq_pool_mutex){+.+.}-{3:3}, at: __alloc_workqueue+0xa55/0x1f20 kernel/workqueue.c:5706 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-08836-gf8eb5bd9a818 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5327 Comm: bch-reclaim/loo Not tainted 6.11.0-syzkaller-08836-gf8eb5bd9a818 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__mutex_trylock_common+0x139/0x2e0 kernel/locking/mutex.c:125 Code: 00 00 49 83 cf 02 eb 4a 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 30 0f b6 04 01 84 c0 0f 85 e8 00 00 00 83 3d 67 8c c8 18 00 <75> 09 83 e3 06 0f 85 8d 00 00 00 4c 8b 74 24 18 eb 16 4c 3b 74 24 RSP: 0018:ffffc90004257720 EFLAGS: 00000246 RAX: 0000000000000004 RBX: 0000000000000000 RCX: ffffffff9a37c903 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88805cb846a0 RBP: ffffc900042577f0 R08: ffff88805cb846a7 R09: 1ffff1100b9708d4 R10: dffffc0000000000 R11: ffffed100b9708d5 R12: ffff88805cb846a0 R13: 1ffff9200084aef0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6eb77052d8 CR3: 000000000e734000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mutex_trylock kernel/locking/mutex.c:152 [inline] __mutex_lock_common kernel/locking/mutex.c:611 [inline] __mutex_lock+0x151/0xd70 kernel/locking/mutex.c:752 btree_write_buffer_flush_seq+0x1a39/0x1bc0 fs/bcachefs/btree_write_buffer.c:509 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565 __bch2_journal_reclaim+0x77d/0xe40 fs/bcachefs/journal_reclaim.c:697 bch2_journal_reclaim_thread+0x174/0x560 fs/bcachefs/journal_reclaim.c:739 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244