INFO: task syz.1.580:8407 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00145-g695caca9345a #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.580 state:D stack:25568 pid:8407 tgid:8407 ppid:5846 task_flags:0x40044c flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:216 sync_inodes_sb+0x28d/0xb50 fs/fs-writeback.c:2821 sync_filesystem+0x176/0x230 fs/sync.c:64 generic_shutdown_super+0x72/0x2d0 fs/super.c:621 kill_block_super+0x44/0x90 fs/super.c:1710 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7368 deactivate_locked_super+0xc6/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1413 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2cad3bfa25 RSP: 002b:00007f2cae151f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f2cad5a6080 RCX: 00007f2cad3bfa25 RDX: 00007f2cae151fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f2cad40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f2cad5a6080 R15: 00007ffe8e832c48 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 3 locks held by kworker/u8:4/81: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90001597c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90001597c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fed5d48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285 5 locks held by kworker/u8:6/2905: 2 locks held by getty/5587: #0: ffff888035f120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 1 lock held by syz.5.69/6249: #0: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #0: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 2 locks held by syz.1.580/8407: #0: ffff8880572ea0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880572ea0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880572ea0e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffff8881433aa7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8881433aa7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.4.727/8997: #0: ffff88807f3b40e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807f3b40e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807f3b40e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffff8881433b47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8881433b47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 3 locks held by kworker/u8:19/12723: 3 locks held by kworker/u8:28/12754: 1 lock held by kmmpd-loop1/13764: #0: ffff8880b863e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 4 locks held by kworker/u8:47/14474: #0: ffff88801beee148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801beee148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90004807c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004807c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fec9510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17a/0xd60 net/core/net_namespace.c:606 #3: ffff88814d2450e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #3: ffff88814d2450e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88814d2450e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x13b/0x440 net/devlink/core.c:506 4 locks held by syz-executor/14561: #0: ffff888036104420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3035 [inline] #0: ffff888036104420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #1: ffff888067977c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8880279b22d8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f77c428 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 7 locks held by syz-executor/14647: #0: ffff888036104420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3035 [inline] #0: ffff888036104420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #1: ffff888048f92888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8880279b23c8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f77c428 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88814d2450e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #4: ffff88814d2450e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88814d2450e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88814d246250 (&devlink->lock_key#26){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8eb3e780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3741 1 lock held by syz-executor/14806: #0: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #0: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 1 lock held by dhcpcd-run-hook/14949: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00145-g695caca9345a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __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:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5946 Comm: kworker/1:6 Not tainted 6.14.0-rc6-syzkaller-00145-g695caca9345a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events drain_vmap_area_work RIP: 0010:trace_hardirqs_on+0x2c/0x40 kernel/trace/trace_preemptirq.c:79 Code: 1e fa 65 8b 05 3d a8 39 7e 85 c0 74 14 48 8b 3c 24 e8 b8 fe ff ff 65 c7 05 25 a8 39 7e 00 00 00 00 e8 08 e8 d2 ff 48 8b 3c 24 <e9> 3f 12 3f 0a 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 RSP: 0018:ffffc90002e2f518 EFLAGS: 00000046 RAX: 5950695bdbc10600 RBX: ffffffff9a845b30 RCX: ffffffff819d4b5a RDX: dffffc0000000000 RSI: ffffffff8c2ac600 RDI: ffffffff8c0b856f RBP: ffffc90002e2f5b0 R08: ffffffff9454c847 R09: 1ffffffff28a9908 R10: dffffc0000000000 R11: fffffbfff28a9909 R12: dffffc0000000000 R13: 1ffff920005c5ea4 R14: ffffc90002e2f540 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f43e45df270 CR3: 000000000e938000 CR4: 0000000000350ef0 Call Trace: <NMI> </NMI> <TASK> __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x8f/0x140 kernel/locking/spinlock.c:194 __debug_check_no_obj_freed lib/debugobjects.c:1108 [inline] debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1129 free_pages_prepare mm/page_alloc.c:1134 [inline] free_frozen_pages+0x4c2/0x10e0 mm/page_alloc.c:2660 kasan_depopulate_vmalloc_pte+0x74/0x90 mm/kasan/shadow.c:408 apply_to_pte_range mm/memory.c:2911 [inline] apply_to_pmd_range mm/memory.c:2955 [inline] apply_to_pud_range mm/memory.c:2991 [inline] apply_to_p4d_range mm/memory.c:3027 [inline] __apply_to_page_range+0x808/0xde0 mm/memory.c:3063 kasan_release_vmalloc+0xa5/0xd0 mm/kasan/shadow.c:529 kasan_release_vmalloc_node mm/vmalloc.c:2196 [inline] purge_vmap_node+0x22f/0x8d0 mm/vmalloc.c:2213 __purge_vmap_area_lazy+0x708/0xae0 mm/vmalloc.c:2304 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2338 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK>