INFO: task kworker/u8:0:12 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:22120 pid:12 tgid:12 ppid:2 task_flags:0x4248060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 io_schedule+0xbf/0x130 kernel/sched/core.c:7724 blk_mq_get_tag+0x566/0xac0 block/blk-mq-tag.c:188 __blk_mq_alloc_requests+0x750/0x1620 block/blk-mq.c:548 blk_mq_get_new_requests block/blk-mq.c:3039 [inline] blk_mq_submit_bio+0x124b/0x26a0 block/blk-mq.c:3179 __submit_bio+0x3cf/0x690 block/blk-core.c:635 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x660/0xd30 block/blk-core.c:751 submit_bio_noacct+0x50d/0x1eb0 block/blk-core.c:874 ext4_io_submit+0xa6/0x140 fs/ext4/page-io.c:404 ext4_do_writepages+0x9cb/0x3490 fs/ext4/inode.c:2820 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2953 do_writepages+0x27a/0x600 mm/page-writeback.c:2636 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2047 wb_writeback+0x7f3/0xb70 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0x8ca/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.0.27:6624 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.27 state:D stack:27864 pid:6624 tgid:6624 ppid:6497 task_flags:0x440040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 io_schedule+0xbf/0x130 kernel/sched/core.c:7724 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0xd9/0x110 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:105 [inline] do_get_write_access+0x93d/0x1320 fs/jbd2/transaction.c:1092 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:242 ext4_reserve_inode_write+0x1be/0x340 fs/ext4/inode.c:6247 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6422 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6459 __mark_inode_dirty+0x1ee/0xe50 fs/fs-writeback.c:2527 generic_update_time+0xcf/0xf0 fs/inode.c:2064 inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x17d/0x1c0 fs/inode.c:2335 ext4_page_mkwrite+0x35e/0x1760 fs/ext4/inode.c:6577 do_page_mkwrite+0x171/0x380 mm/memory.c:3378 do_shared_fault mm/memory.c:5666 [inline] do_fault mm/memory.c:5728 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6069 [inline] __handle_mm_fault+0x3829/0x5490 mm/memory.c:6212 handle_mm_fault+0x589/0xd10 mm/memory.c:6381 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f251ae58589 RSP: 002b:00007ffd47fbdf60 EFLAGS: 00010202 RAX: 0000001b31a60000 RBX: 00007f251bca5720 RCX: 0000000000000003 RDX: 0000001b31a5ffff RSI: 0000000000000008 RDI: 00007f251bca5720 RBP: 00000000fffffc03 R08: 0000000000000000 R09: 0000000000000000 R10: 00007f251bca5700 R11: 0000000000000000 R12: 00007f251b176038 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801eebf148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90000117d10 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88814d6920e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:563 #3: ffff88814d694b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x27a/0x600 mm/page-writeback.c:2636 1 lock held by khungtaskd/31: #0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 4 locks held by kworker/u8:6/1149: #0: ffff8880b843a418 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606 #1: ffff8880b8424088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x201/0x8e0 kernel/sched/psi.c:975 #2: ffffffff9b08b028 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_deactivate+0x135/0x3a0 lib/debugobjects.c:873 #3: ffffffff9b05aea8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818 2 locks held by getty/5606: #0: ffff8880322740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz.0.27/6624: #0: ffff88807b723a88 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1327 #1: ffff88814d692520 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3378 #2: ffff88814d696950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 2 locks held by syz-executor/6811: #0: ffff88814d692428 (sb_writers#4){.+.+}-{0:0}, at: filename_create+0x10e/0x4a0 fs/namei.c:4141 #1: ffff88807e182090 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline] #1: ffff88807e182090 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x1bb/0x4a0 fs/namei.c:4148 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 0b 6f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 77 25 00 fb f4 8c fb 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6 RAX: 000000000015a5cb RBX: 0000000000000000 RCX: ffffffff8b849c69 RDX: 0000000000000000 RSI: ffffffff8de2d10c RDI: ffffffff8c157960 RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086645 R10: ffff8880b843322b R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e297780 R14: ffffffff90a9a650 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124720000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558951d43658 CR3: 000000000e382000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:745 start_kernel+0x3ee/0x4d0 init/main.c:1102 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148