INFO: task kworker/u8:13:1467 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:13 state:D stack:21296 pid:1467 tgid:1467 ppid:2 task_flags:0x4248060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 io_schedule+0x80/0xe0 kernel/sched/core.c:8212 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_mb_mark_context+0x171/0xec0 fs/ext4/mballoc.c:4112 ext4_mb_mark_diskspace_used+0x338/0x760 fs/ext4/mballoc.c:4241 ext4_mb_new_blocks+0x106f/0x4540 fs/ext4/mballoc.c:6329 ext4_ext_map_blocks+0x13f1/0x5680 fs/ext4/extents.c:4469 ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:630 ext4_map_blocks+0x791/0x12c0 fs/ext4/inode.c:823 mpage_map_one_extent fs/ext4/inode.c:2379 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2469 [inline] ext4_do_writepages+0x239b/0x4770 fs/ext4/inode.c:2938 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3032 do_writepages+0x338/0x560 mm/page-writeback.c:2560 __writeback_single_inode+0x136/0x1230 fs/fs-writeback.c:1788 writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2099 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2175 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2286 wb_check_old_data_flush fs/fs-writeback.c:2390 [inline] wb_do_writeback fs/fs-writeback.c:2469 [inline] wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2497 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task jbd2/sda1-8:4923 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25784 pid:4923 tgid:4923 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 io_schedule+0x80/0xe0 kernel/sched/core.c:8212 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_buffer include/linux/buffer_head.h:418 [inline] jbd2_journal_commit_transaction+0x2f26/0x5ba0 fs/jbd2/commit.c:834 kjournald2+0x3bc/0x750 fs/jbd2/journal.c:200 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:5582 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21864 pid:5582 tgid:5582 ppid:5581 task_flags:0x440100 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 io_schedule+0x80/0xe0 kernel/sched/core.c:8212 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6897 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 wp_page_shared mm/memory.c:4217 [inline] do_wp_page+0x20a7/0x3d20 mm/memory.c:4440 handle_pte_fault mm/memory.c:6582 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xd69/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fd2af1b01e3 RSP: 002b:00007ffee789fee0 EFLAGS: 00010202 RAX: 00007fd2ac33e46c RBX: 00007ffee78a0010 RCX: 0000000000000000 RDX: 00007fd2ac33e468 RSI: 0000000000000008 RDI: 00007ffee78a0010 RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffee789fff0 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000001b94 R14: ffffffffffffe46c R15: 0000000000000000 INFO: task syz.1.42:5898 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.42 state:D stack:26056 pid:5898 tgid:5898 ppid:5604 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 io_schedule+0x80/0xe0 kernel/sched/core.c:8212 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] file_update_time_flags+0x39f/0x450 fs/inode.c:2483 ext4_page_mkwrite+0x225/0x1150 fs/ext4/inode.c:6897 do_page_mkwrite+0x14a/0x310 mm/memory.c:3816 do_shared_fault mm/memory.c:6076 [inline] do_fault mm/memory.c:6138 [inline] do_pte_missing+0x734/0x28f0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0xf64/0x28c0 mm/memory.c:6876 do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f05b86b2809 RSP: 002b:00007ffd240327b0 EFLAGS: 00010202 RAX: 0000001b32824000 RBX: 0000000000000000 RCX: 00000000003ffde8 RDX: 0000001b32823ffc RSI: 00000000003ffde8 RDI: 00007f05b9595700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f05b8a52000 R10: 00007f05b9595700 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000008a9f R14: ffffffff816d5060 R15: 00007f05b9595720 INFO: task syz.4.46:5909 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.46 state:D stack:26272 pid:5909 tgid:5909 ppid:5600 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 io_schedule+0x80/0xe0 kernel/sched/core.c:8212 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] touch_atime+0x568/0x670 fs/inode.c:2328 file_accessed include/linux/fs.h:2277 [inline] ext4_file_mmap_prepare+0x286/0x460 fs/ext4/file.c:901 vfs_mmap_prepare include/linux/fs.h:2069 [inline] call_mmap_prepare mm/vma.c:2776 [inline] __mmap_region mm/vma.c:2863 [inline] mmap_region+0xe9f/0x2240 mm/vma.c:2964 do_mmap+0xe0e/0x1310 mm/mmap.c:573 vm_mmap_pgoff+0x275/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4a6/0x720 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4c24cdec2 RSP: 002b:00007ffc7c1d83d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b32864000 RCX: 00007ff4c24cdec2 RDX: 0000000000000003 RSI: 00000000005c0000 RDI: 0000001b32864000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 0000000000000008 R13: 00000000000927c0 R14: 000000000001f97c R15: 00007ffc7c1d86b0 INFO: task syz.2.45:5910 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.45 state:D stack:27160 pid:5910 tgid:5910 ppid:5599 task_flags:0x440040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 io_schedule+0x80/0xe0 kernel/sched/core.c:8212 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258 __wait_on_bit+0xac/0x2f0 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:106 [inline] do_get_write_access+0x671/0x1090 fs/jbd2/transaction.c:1113 jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263 __ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249 ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509 __ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731 __mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729 generic_update_time fs/inode.c:2253 [inline] touch_atime+0x568/0x670 fs/inode.c:2328 file_accessed include/linux/fs.h:2277 [inline] ext4_file_mmap_prepare+0x286/0x460 fs/ext4/file.c:901 vfs_mmap_prepare include/linux/fs.h:2069 [inline] call_mmap_prepare mm/vma.c:2776 [inline] __mmap_region mm/vma.c:2863 [inline] mmap_region+0xe9f/0x2240 mm/vma.c:2964 do_mmap+0xe0e/0x1310 mm/mmap.c:573 vm_mmap_pgoff+0x275/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4a6/0x720 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d1441dec2 RSP: 002b:00007ffd2eb5c6e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000001b32564000 RCX: 00007f3d1441dec2 RDX: 0000000000000003 RSI: 00000000005c0000 RDI: 0000001b32564000 RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000206 R12: 000000000000000c R13: 00000000000927c0 R14: 000000000001f659 R15: 00007ffd2eb5c9c0 Showing all locks held in the system: locks held by pr/ttyS0/17: 3, last CPU#0: #0: ffffffff8e09d5f8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff8e09d5f8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #0: ffffffff8e09d5f8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 #1: ffffffff99e9c1f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_emit_one kernel/printk/nbcon.c:1137 [inline] #1: ffffffff99e9c1f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_kthread_func+0x64c/0x880 kernel/printk/nbcon.c:1271 #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by khungtaskd/39: 1, last CPU#1: #0: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:13/1467: 6, on CPU#1: #0: ffff88801d6dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801d6dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801d6dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801d6dc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc900069cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc900069cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc900069cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc900069cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffff8880350120e0 (&type->s_umount_key#33){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:688 #3: ffff888034f68d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff888034f68d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1887 [inline] #3: ffff888034f68d98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3031 #4: ffff888034f56bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 #5: ffff8880401c8288 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0x77d/0x12c0 fs/ext4/inode.c:822 locks held by klogd/4950: 3, last CPU#1: #0: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x550 net/core/sock.c:3658 #1: ffff8880336d1518 (&si->socket.wq.wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #1: ffff8880336d1518 (&si->socket.wq.wait){+.+.}-{3:3}, at: __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:125 #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c3b40 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57 locks held by getty/5350: 2, on CPU#0: #0: ffff88803603b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044c32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5582: 3, on CPU#1: #0: ffff888035d14d08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6896 #2: ffff888034f56bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.1.42/5898: 3, on CPU#1: #0: ffff888025c24088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff888035012688 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x203/0x1150 fs/ext4/inode.c:6896 #2: ffff888034f56bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.4.46/5909: 3, on CPU#1: #0: ffff88803490ba30 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline] #0: ffff88803490ba30 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1e0/0x4e0 mm/util.c:579 #1: ffff888035012510 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2277 [inline] #1: ffff888035012510 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x286/0x460 fs/ext4/file.c:901 #2: ffff888034f56bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 locks held by syz.2.45/5910: 3, on CPU#1: #0: ffff8880328f8430 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline] #0: ffff8880328f8430 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1e0/0x4e0 mm/util.c:579 #1: ffff888035012510 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2277 [inline] #1: ffff888035012510 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x286/0x460 fs/ext4/file.c:901 #2: ffff888034f56bb0 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 17 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:416 Code: 7e 65 fc 44 89 f9 d3 e5 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 1c 65 d1 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 d7 09 f9 05 cc 44 89 f9 80 e1 07 38 c1 RSP: 0018:ffffc90000167900 EFLAGS: 00000202 RAX: 000000000000002b RBX: 000000000000002b RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000003f8 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff85610f00 R12: dffffc0000000000 R13: 000000000000002b R14: ffffffff99e9c220 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125bd1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8bf4069480 CR3: 000000000dfb0000 CR4: 00000000003526f0 Call Trace: serial_port_out include/linux/serial_core.h:817 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3287 [inline] __serial8250_console_fifo_write+0x1ec/0x3f0 drivers/tty/serial/8250/8250_port.c:3359 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline] serial8250_console_write+0xac5/0x1230 drivers/tty/serial/8250/8250_port.c:3493 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245