INFO: task jbd2/sda1-8:5163 blocked for more than 143 seconds. Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25640 pid:5163 tgid:5163 ppid:2 task_flags:0x240040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 jbd2_journal_wait_updates+0x11e/0x240 fs/jbd2/transaction.c:843 jbd2_journal_commit_transaction+0x828/0x6830 fs/jbd2/commit.c:454 kjournald2+0x1f4/0x760 fs/jbd2/journal.c:201 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:5813 blocked for more than 143 seconds. Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:23624 pid:5813 tgid:5813 ppid:5811 task_flags:0x400100 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 wait_transaction_locked+0x1a1/0x230 fs/jbd2/transaction.c:152 add_transaction_credits+0x110/0xe60 fs/jbd2/transaction.c:222 start_this_handle+0x3e7/0x1410 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x195/0x690 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_dirty_inode+0xa1/0x130 fs/ext4/inode.c:6100 __mark_inode_dirty+0x1eb/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/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fd00bc77dcf RSP: 002b:00007fffe8b3c2e0 EFLAGS: 00010202 RAX: 00007fd00a0ec000 RBX: 00005555890f7fd0 RCX: 0000000000000007 RDX: 1ffffffff0963387 RSI: 00005555890f2918 RDI: 0000000000000080 RBP: 00007fffe8b3c5d0 R08: 00005555890f2978 R09: 0000000000000670 R10: 0000000000000001 R11: 00007fffe8b3c7e0 R12: 00007fffe8b3c630 R13: 0000000000000004 R14: 00007fffe8b3c350 R15: 00007fffe8b3c420 INFO: task kworker/u8:13:7141 blocked for more than 143 seconds. Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:13 state:D stack:24168 pid:7141 tgid:7141 ppid:2 task_flags:0x4248060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 io_schedule+0xbf/0x130 kernel/sched/core.c:7742 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247 __wait_on_bit+0x62/0x180 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] __wait_on_buffer+0x64/0x70 fs/buffer.c:123 wait_on_buffer include/linux/buffer_head.h:422 [inline] ext4_read_bh+0x2ad/0x310 fs/ext4/super.c:207 __read_extent_tree_block+0x370/0x640 fs/ext4/extents.c:571 ext4_find_extent+0x4a2/0xa70 fs/ext4/extents.c:938 ext4_ext_map_blocks+0x27d/0x5d60 fs/ext4/extents.c:4205 ext4_map_create_blocks fs/ext4/inode.c:520 [inline] ext4_map_blocks+0x45b/0x1390 fs/ext4/inode.c:706 mpage_map_one_extent fs/ext4/inode.c:2224 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2277 [inline] ext4_do_writepages+0x1a2c/0x3490 fs/ext4/inode.c:2739 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2829 do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976 wb_writeback+0x419/0xb70 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x14d/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.0.451:7724 blocked for more than 144 seconds. Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.451 state:D stack:28856 pid:7724 tgid:7710 ppid:5824 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 wb_wait_for_completion+0x1af/0x2b0 fs/fs-writeback.c:216 __writeback_inodes_sb_nr+0x1d7/0x270 fs/fs-writeback.c:2747 sync_filesystem+0xbb/0x290 fs/sync.c:54 fs_bdev_sync+0x2c/0x40 fs/super.c:1435 blkdev_flushbuf block/ioctl.c:433 [inline] blkdev_common_ioctl+0x1742/0x2480 block/ioctl.c:571 blkdev_ioctl+0x1cb/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5eebd8e969 RSP: 002b:00007f5eecb16038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5eebfb6240 RCX: 00007f5eebd8e969 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000004 RBP: 00007f5eebe10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5eebfb6240 R15: 00007ffeea2355c8 INFO: task syz.1.457:7739 blocked for more than 144 seconds. Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.457 state:D stack:26488 pid:7739 tgid:7739 ppid:5825 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 wait_transaction_locked+0x1a1/0x230 fs/jbd2/transaction.c:152 add_transaction_credits+0x110/0xe60 fs/jbd2/transaction.c:222 start_this_handle+0x3e7/0x1410 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x195/0x690 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_dirty_inode+0xa1/0x130 fs/ext4/inode.c:6100 __mark_inode_dirty+0x1eb/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/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fa0d146eada RSP: 002b:00007ffc38dcb5e0 EFLAGS: 00010202 RAX: 0000001b2faf4000 RBX: 00007fa0d22e5720 RCX: 0000001b2faf3ff8 RDX: 0000001b2f720220 RSI: 0000000000000008 RDI: 00007fa0d22e5720 RBP: ffffffff8b672158 R08: 00007fa0d17b6038 R09: 00007fa0d17a2000 R10: 00007fa0d0bff008 R11: 0000000000000010 R12: 0000000000000010 R13: 000000000000014e R14: ffffffff8b67265a R15: 0000000000000168 INFO: task syz.3.458:7744 blocked for more than 145 seconds. Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.458 state:D stack:28792 pid:7744 tgid:7744 ppid:5823 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 wait_transaction_locked+0x1a1/0x230 fs/jbd2/transaction.c:152 add_transaction_credits+0x110/0xe60 fs/jbd2/transaction.c:222 start_this_handle+0x3e7/0x1410 fs/jbd2/transaction.c:403 jbd2__journal_start+0x394/0x6a0 fs/jbd2/transaction.c:501 __ext4_journal_start_sb+0x195/0x690 fs/ext4/ext4_jbd2.c:114 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_dirty_inode+0xa1/0x130 fs/ext4/inode.c:6100 __mark_inode_dirty+0x1eb/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/0x1750 fs/ext4/inode.c:6221 do_page_mkwrite+0x171/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7efea726547b RSP: 002b:00007ffeb6dd9010 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2f920000 RSI: 0000000000600000 RDI: 00007efea7498d50 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000031915 R15: 00007ffeb6dd92c0 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 1 lock held by klogd/5190: #0: ffff8880b8539f18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:605 2 locks held by getty/5582: #0: ffff88814da4a0a0 (&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 2 locks held by syz-executor/5813: #0: ffff88802e1fc088 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff888031bcc518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 5 locks held by kworker/u8:13/7141: #0: ffff88802168c948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003d57d18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff888031bceb98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 #3: ffff888034cf0950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 #4: ffff88807b1665d8 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x355/0x1390 fs/ext4/inode.c:705 5 locks held by kworker/u8:15/7143: 1 lock held by syz.0.451/7724: #0: ffff888031bcc0e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888031bcc0e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:120 2 locks held by syz.1.457/7739: #0: ffff888032ecf808 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff888031bcc518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 2 locks held by syz.3.458/7744: #0: ffff888027aae808 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff888031bcc518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 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: 7143 Comm: kworker/u8:15 Tainted: G U 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: 0x0 (events_unbound) RIP: 0010:__list_del include/linux/list.h:196 [inline] RIP: 0010:__list_del_entry include/linux/list.h:218 [inline] RIP: 0010:__list_del_entry include/linux/list.h:213 [inline] RIP: 0010:list_move_tail include/linux/list.h:310 [inline] RIP: 0010:move_linked_works+0x11d/0x2f0 kernel/workqueue.c:1147 Code: 00 00 48 8d 7a 08 4c 8b 7b 10 48 89 f9 48 c1 e9 03 80 3c 29 00 0f 85 5e 01 00 00 4c 89 f9 4c 89 7a 08 48 c1 e9 03 80 3c 29 00 <0f> 85 34 01 00 00 49 89 17 e8 05 55 38 00 48 8b 44 24 08 80 38 00 RSP: 0018:ffffc90003e57d20 EFLAGS: 00000046 RAX: 1ffff1100e6150ce RBX: ffff8880730a8660 RCX: 1ffff1100369400c RDX: ffff88801b4a0060 RSI: ffffffff81825577 RDI: ffff88801b4a0068 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880730a8668 R13: ffff88801b4a0058 R14: ffff888034ce5a40 R15: ffff88801b4a0060 FS: 0000000000000000(0000) GS:ffff8881249ed000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055becefbcce8 CR3: 000000000e180000 CR4: 00000000003526f0 Call Trace: assign_work+0x19b/0x250 kernel/workqueue.c:1199 worker_thread+0x5f6/0xf10 kernel/workqueue.c:3399 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245