INFO: task kworker/u8:8:3008 blocked for more than 143 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:8 state:D stack:22360 pid:3008 tgid:3008 ppid:2 task_flags:0x4248160 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_lock+0x112/0x1a0 kernel/sched/wait_bit.c:90 out_of_line_wait_on_bit_lock+0xd9/0x110 kernel/sched/wait_bit.c:117 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer+0x67/0x70 fs/buffer.c:71 lock_buffer include/linux/buffer_head.h:434 [inline] do_get_write_access+0x8cd/0x12a0 fs/jbd2/transaction.c:968 jbd2_journal_get_write_access+0x1d6/0x280 fs/jbd2/transaction.c:1241 __ext4_journal_get_write_access+0x6a/0x340 fs/ext4/ext4_jbd2.c:241 ext4_mb_mark_context+0x175/0xd40 fs/ext4/mballoc.c:4001 ext4_mb_mark_diskspace_used+0x466/0x8c0 fs/ext4/mballoc.c:4131 ext4_mb_new_blocks+0xa5b/0x4f00 fs/ext4/mballoc.c:6233 ext4_ext_map_blocks+0x1b95/0x5d60 fs/ext4/extents.c:4379 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 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2047 wb_writeback+0x7f3/0xb70 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+0x748/0xbe0 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 jbd2/sda1-8:5161 blocked for more than 144 seconds. Tainted: G U I 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:26520 pid:5161 tgid:5161 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:5817 blocked for more than 144 seconds. Tainted: G U I 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:23080 pid:5817 tgid:5817 ppid:5815 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 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/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: 0033:0x7f186a2689c5 RSP: 002b:00007ffd42c99c30 EFLAGS: 00010206 RAX: 00007f18651f092c RBX: 00007ffd42c99d30 RCX: 0000000000000000 RDX: 00007f18651f0928 RSI: 0000000000000008 RDI: 00007ffd42c99d30 RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffd42c99d10 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000000f6d4 R14: ffffffffffff092c R15: 000000000000f6d4 INFO: task syz.5.10483:30985 blocked for more than 144 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.10483 state:D stack:27432 pid:30985 tgid:30985 ppid:17170 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: 0033:0x7fa65386eada RSP: 002b:00007ffde6868260 EFLAGS: 00010202 RAX: 0000001b3351c000 RBX: 00007fa6546e5720 RCX: 0000001b3351bff8 RDX: 0000001b33120220 RSI: 0000000000000008 RDI: 00007fa6546e5720 RBP: ffffffff819ad932 R08: 00007fa653bb6038 R09: 00007fa653ba2000 R10: 00007fa652fff008 R11: 0000000000000002 R12: 0000000000000002 R13: 000000000000017c R14: ffffffff819ad439 R15: 000000000000024d INFO: task syz.3.10486:30992 blocked for more than 145 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.10486 state:D stack:28792 pid:30992 tgid:30992 ppid:5829 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: 0033:0x7fd0a1e6547b RSP: 002b:00007ffc230ddbc0 EFLAGS: 00010246 RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2fd20000 RSI: 0000000000400000 RDI: 00007fd0a2098d50 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000084006 R15: 00007ffc230dde70 INFO: task syz.6.10487:30994 blocked for more than 145 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.10487 state:D stack:28632 pid:30994 tgid:30994 ppid:26047 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: 0033:0x7fd09d46547b RSP: 002b:00007ffea6b65690 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2cb20000 RSI: 0000000000600000 RDI: 00007fd09d698d50 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000008405c R15: 00007ffea6b65940 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 6 locks held by kworker/u8:8/3008: #0: ffff8880216fd148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000bcc7d18 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88814de900e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:562 #3: ffff88814de92b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x1b2/0x820 mm/page-writeback.c:2656 #4: ffff88814de94950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 #5: ffff88807a67efc0 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x355/0x1390 fs/ext4/inode.c:705 2 locks held by syz-executor/5817: #0: ffff88807941e808 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814de90518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 2 locks held by getty/19897: #0: ffff8880341800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000b3cd2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz.5.10483/30985: #0: ffff8880353386c8 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814de90518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 2 locks held by syz.3.10486/30992: #0: ffff888032973088 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814de90518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 2 locks held by syz.6.10487/30994: #0: ffff88803419de48 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814de90518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U I 6.15.0-rc4-syzkaller-00040-g8bac8898fe39 #0 PREEMPT(full) Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND 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