INFO: task kworker/u8:4:68 blocked for more than 143 seconds. Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:20248 pid:68 tgid:68 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0xc4b/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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 INFO: task syz.0.68:6430 blocked for more than 143 seconds. Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.68 state:D stack:25952 pid:6430 tgid:6404 ppid:5831 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 exfat_lookup+0x143/0x1e70 fs/exfat/namei.c:726 lookup_open fs/namei.c:3627 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x11a7/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_open fs/open.c:1425 [inline] __se_sys_open fs/open.c:1421 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1421 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: 0033:0x7fee87b7ff19 RSP: 002b:00007fee88977058 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fee87d46160 RCX: 00007fee87b7ff19 RDX: 0000000000000000 RSI: 000000000010b942 RDI: 0000000020000080 RBP: 00007fee87bf3986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fee87d46160 R15: 00007ffce15c4ba8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 2 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 4 locks held by kworker/u8:2/35: 3 locks held by kworker/1:1/57: 4 locks held by kworker/u8:4/68: #0: ffff8881416dd948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881416dd948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000217fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000217fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff8880247ee0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff8880247ec0e8 (&sbi->s_lock){+.+.}-{4:4}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 3 locks held by kworker/u8:5/1104: #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/0x1840 kernel/workqueue.c:3310 #1: ffffc90003c0fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003c0fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 5 locks held by kworker/u8:6/2891: 2 locks held by dhcpcd/5487: #0: ffffffff8fc827c8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x661/0x8e0 net/socket.c:1290 #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0x112/0x9d0 net/8021q/vlan.c:553 2 locks held by getty/5577: #0: ffff8880312130a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by syz.0.68/6406: 3 locks held by syz.0.68/6430: #0: ffff8880247ee420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88807e620f80 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #1: ffff88807e620f80 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: open_last_lookups fs/namei.c:3745 [inline] #1: ffff88807e620f80 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: path_openat+0x89a/0x3590 fs/namei.c:3984 #2: ffff8880247ec0e8 (&sbi->s_lock){+.+.}-{4:4}, at: exfat_lookup+0x143/0x1e70 fs/exfat/namei.c:726 2 locks held by syz-executor/7111: #0: ffff88805726c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805726c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88805726c0e0 (&type->s_umount_key#31){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8e9f8a88 (lock#3){+.+.}-{4:4}, at: __lru_add_drain_all+0x66/0x560 mm/swap.c:798 2 locks held by syz-executor/7644: #0: ffffffff8f4472e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8f4472e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8f4472e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:555 #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #1: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd04/0x24f0 net/core/rtnetlink.c:4006 2 locks held by syz.7.248/7802: 2 locks held by syz.4.250/7808: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:preempt_count_add+0x44/0x190 kernel/sched/core.c:5851 Code: 00 00 00 fc ff df 42 0f b6 04 38 84 c0 0f 85 ed 00 00 00 83 3d 5c 17 cb 18 00 75 07 65 8b 05 1b 52 96 7e 65 01 1d 14 52 96 7e <48> c7 c0 c0 99 38 9a 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e4 00 RSP: 0018:ffffc90000117510 EFLAGS: 00000282 RAX: 0000000080000001 RBX: 0000000000000001 RCX: ffffffff9a389903 RDX: dffffc0000000000 RSI: ffffffff872abb9c RDI: 0000000000000001 RBP: ffffc90000117638 R08: 0000000000000006 R09: ffffc900001176f0 R10: ffffc90000117650 R11: ffffffff818b36a0 R12: dffffc0000000000 R13: ffffc90000117600 R14: ffffffff872abb9c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1aa516a000 CR3: 0000000035188000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xb0/0x22d0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x196/0x430 mm/slub.c:4746 skb_kfree_head net/core/skbuff.c:1086 [inline] skb_free_head net/core/skbuff.c:1098 [inline] skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x9f/0xf0 net/core/skbuff.c:1436 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x7cc/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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