INFO: task syz.5.7517:22988 blocked for more than 143 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.7517 state:D stack:26488 pid:22988 tgid:22988 ppid:8646 task_flags:0x440140 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 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] do_get_write_access+0x93d/0x12a0 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:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __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: 0033:0x7f873b26f282 RSP: 002b:00007ffe2973d900 EFLAGS: 00010202 RAX: 000000000000b008 RBX: 00007f873c0e5720 RCX: 0000000000000000 RDX: 0000001b2e815000 RSI: 0000000000000008 RDI: 00007f873c0e5720 RBP: 000000000000069a R08: 00007f873a9ff0d0 R09: 00007f873b5a2000 R10: 00007f873a9ff008 R11: 0000000000000001 R12: ffffffff822a95de R13: 00007f873b5b6038 R14: 00000000000001e5 R15: ffffffffffff5000 INFO: task syz.3.7521:22998 blocked for more than 143 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.7521 state:D stack:28344 pid:22998 tgid:22998 ppid:5828 task_flags:0x440040 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 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] do_get_write_access+0x93d/0x12a0 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:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __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: 0033:0x7f8c9fc6eada RSP: 002b:00007ffc87be3cf0 EFLAGS: 00010202 RAX: 0000001b30320000 RBX: 00007f8ca0ae5720 RCX: 0000001b3031fff8 RDX: 00000000005ffde8 RSI: 00000000005ffde8 RDI: 00007f8ca0ae5700 RBP: ffffffff815df230 R08: 00007f8c9ffb6038 R09: 00007f8c9ffa2000 R10: 00007f8c9f3ff008 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: ffffffff815dfb5a R15: 0000000000000001 INFO: task syz.1.7522:22999 blocked for more than 144 seconds. Tainted: G U I 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.7522 state:D stack:28168 pid:22999 tgid:22999 ppid:5827 task_flags:0x440040 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 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] do_get_write_access+0x93d/0x12a0 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:241 ext4_reserve_inode_write+0x1be/0x320 fs/ext4/inode.c:5892 __ext4_mark_inode_dirty+0x197/0x870 fs/ext4/inode.c:6066 ext4_dirty_inode+0xd9/0x130 fs/ext4/inode.c:6103 __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: 0033:0x7f716906547b RSP: 002b:00007ffd6e91f640 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b2fb20000 RSI: 0000000000600000 RDI: 00007f7169298d50 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000009c8cc R15: 00007ffd6e91f8f0 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 3 locks held by syz-executor/5816: #0: ffff888061359948 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e0ee518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff88814e0f2950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 2 locks held by getty/20154: #0: ffff888031c4d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900042332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz.5.7517/22988: #0: ffff8880641ece48 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e0ee518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff88814e0f2950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 3 locks held by syz.3.7521/22998: #0: ffff88807c829bc8 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e0ee518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff88814e0f2950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 3 locks held by syz.1.7522/22999: #0: ffff88802a2b0588 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e0ee518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff88814e0f2950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 3 locks held by syz.7.7523/23001: #0: ffff88802dce5a88 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x452/0x1370 arch/x86/mm/fault.c:1328 #1: ffff88814e0ee518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x171/0x380 mm/memory.c:3287 #2: ffff88814e0f2950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x5e4/0x1410 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U I 6.15.0-rc4-syzkaller-00147-gebd297a2affa #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