INFO: task syz.1.8:5347 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-04003-gfc1dc0d50780 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.8 state:D stack:18912 pid:5347 tgid:5346 ppid:5223 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 rwsem_down_write_slowpath+0xeeb/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 do_remount fs/namespace.c:3044 [inline] path_mount+0xbdb/0xfa0 fs/namespace.c:3826 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 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: 0033:0x7f186a57f69a RSP: 002b:00007f1869ffee68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f1869ffeef0 RCX: 00007f186a57f69a RDX: 0000000020000f40 RSI: 0000000020000f00 RDI: 0000000000000000 RBP: 0000000020000f40 R08: 00007f1869ffeef0 R09: 0000000001a4243a R10: 0000000001a4243a R11: 0000000000000246 R12: 0000000020000f00 R13: 00007f1869ffeeb0 R14: 0000000000000000 R15: 00000000200008c0 INFO: task syz.2.9:5409 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-04003-gfc1dc0d50780 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.9 state:D stack:25400 pid:5409 tgid:5355 ppid:5225 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 rwsem_down_read_slowpath kernel/locking/rwsem.c:1086 [inline] __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x705/0xa40 kernel/locking/rwsem.c:1528 __super_lock fs/super.c:58 [inline] super_lock+0x27c/0x400 fs/super.c:120 super_lock_shared fs/super.c:139 [inline] iterate_supers+0x8c/0x190 fs/super.c:931 ksys_sync+0xbd/0x1c0 fs/sync.c:102 __do_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f825237def9 RSP: 002b:00007f825319a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f8252536058 RCX: 00007f825237def9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f82523f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8252536058 R15: 00007ffc5b94a0e8 Showing all locks held in the system: 4 locks held by kworker/u8:0/11: #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fcb40d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8e93dd00 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4486 1 lock held by khungtaskd/30: #0: ffffffff8e938a60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e938a60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e938a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 3 locks held by kworker/u8:11/3010: #0: ffff88801eaf4948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801eaf4948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000a38fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000a38fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 1 lock held by klogd/4669: 2 locks held by getty/4977: #0: ffff8880302330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:4/5288: #0: ffff88801ad5c948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801ad5c948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc900031afd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc900031afd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff888029290190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff888029290190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849 1 lock held by syz.1.8/5347: #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: do_remount fs/namespace.c:3044 [inline] #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: path_mount+0xbdb/0xfa0 fs/namespace.c:3826 1 lock held by syz.2.9/5409: #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 3 locks held by bch-reclaim/loo/5366: 1 lock held by syz.5.184/6521: #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz.3.215/6670: #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 7 locks held by syz-executor/7050: #0: ffff888035128420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2930 [inline] #0: ffff888035128420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff88805275f488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8880286a5e18 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f55f6a8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88802d5d80e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff88802d5d80e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff88802d5d80e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1292 #5: ffff88802d5da250 (&devlink->lock_key#11){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8e93de38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #6: ffffffff8e93de38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:965 1 lock held by syz.1.303/7156: #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff888029d500e0 (&type->s_umount_key#72){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz.2.327/7282: 2 locks held by syz.0.329/7292: 2 locks held by dhcpcd-run-hook/7293: 3 locks held by syz.3.330/7295: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-syzkaller-04003-gfc1dc0d50780 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5366 Comm: bch-reclaim/loo Not tainted 6.11.0-syzkaller-04003-gfc1dc0d50780 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__lock_acquire+0x84d/0x2050 kernel/locking/lockdep.c:5149 Code: 24 30 4c 8d ac c1 00 0b 00 00 48 c7 c0 c0 b9 38 9a 48 c1 e8 03 48 89 44 24 68 48 c7 c0 50 eb 1b 90 48 c1 e8 03 48 89 44 24 70 <4d> 89 ef 41 83 fc 31 0f 83 1e 02 00 00 4c 89 f8 48 c1 e8 03 0f b6 RSP: 0018:ffffc900047175b0 EFLAGS: 00000016 RAX: 1ffffffff2037d6a RBX: 0000000000000004 RCX: ffff888025768000 RDX: dffffc0000000000 RSI: ffff888025768ae0 RDI: 000000000000000a RBP: 00000000ffffffff R08: ffffffff9423494f R09: 1ffffffff2846929 R10: dffffc0000000000 R11: fffffbfff284692a R12: 0000000000000000 R13: ffff888025768b00 R14: 0000000000000000 R15: ffff888025768b50 FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c416158 CR3: 000000007a1a4000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __bch2_next_write_buffer_flush_journal_buf+0x70/0x2a0 fs/bcachefs/journal.c:871 bch2_next_write_buffer_flush_journal_buf+0xa3/0x1b0 fs/bcachefs/journal.c:904 fetch_wb_keys_from_journal fs/bcachefs/btree_write_buffer.c:486 [inline] btree_write_buffer_flush_seq+0x18c/0x1bc0 fs/bcachefs/btree_write_buffer.c:503 bch2_btree_write_buffer_journal_flush+0x4e/0x80 fs/bcachefs/btree_write_buffer.c:525 journal_flush_pins+0x5f9/0xb20 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244