INFO: task syz-executor:4173 blocked 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:22832 pid: 4173 ppid: 4171 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 wp_page_shared+0x163/0x6c0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1fbd/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7f765a407ad6 RSP: 002b:00007ffd2cb88d50 EFLAGS: 00010202 RAX: 00007f765838e000 RBX: 0000555586853240 RCX: 0000000000000004 RDX: 00000000000011ea RSI: 0000555586859050 RDI: 0000000000000010 RBP: 00007ffd2cb89250 R08: 0000555586859138 R09: 0000000000000086 R10: 000055558683fe90 R11: 00007f765a783e20 R12: 00007ffd2cb89090 R13: 00007ffd2cb88e80 R14: 585858582e7a7973 R15: 00007ffd2cb88dd0 INFO: task syz.0.1805:9781 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1805 state:D stack:27504 pid: 9781 ppid: 4188 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7ff05b18aba9 RSP: 002b:00007fff53da0260 EFLAGS: 00010202 RAX: 0000001b32723000 RBX: ffffffff81afe51d RCX: 0000001b32722ff8 RDX: 0000001b3232421c RSI: 0000000000000008 RDI: 00007ff05c06c720 RBP: 00000000000001fd R08: 00007ff05b527000 R09: 00007ff05b529000 R10: 0000000081afe521 R11: 0000000000000002 R12: 00007ff05b53d128 R13: 0000000000002b83 R14: ffffffff81afe1bc R15: 00007ff05c06c720 INFO: task syz.9.1806:9789 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.1806 state:D stack:27408 pid: 9789 ppid: 8078 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7fbe36ab3c09 RSP: 002b:00007ffc37568cb0 EFLAGS: 00010202 RAX: 0000001b34324000 RBX: 0000000000000000 RCX: 00000000003ffde8 RDX: 0000001b34323ffc RSI: 00000000003ffde8 RDI: 00007fbe37995700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fbe36e52000 R10: 00007fbe37995700 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000000070a R14: ffffffff819d82f4 R15: 00007fbe37995720 INFO: task syz.6.1807:9802 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1807 state:D stack:27664 pid: 9802 ppid: 7561 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit kernel/sched/wait_bit.c:49 [inline] out_of_line_wait_on_bit+0x173/0x230 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x134/0xe40 fs/jbd2/transaction.c:1116 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1251 __ext4_journal_get_write_access+0x24d/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x203/0x2e0 fs/ext4/inode.c:5866 __ext4_mark_inode_dirty+0x13b/0x6c0 fs/ext4/inode.c:6050 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6087 __mark_inode_dirty+0x2c8/0xc90 fs/fs-writeback.c:2480 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x3c0/0x440 fs/inode.c:2083 ext4_page_mkwrite+0x1bc/0x1250 fs/ext4/inode.c:6205 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1e47/0x4440 mm/memory.c:4883 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7f2c8583cea3 RSP: 002b:00007ffd5fa6c9b0 EFLAGS: 00010246 RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b2d464000 RDX: 0000001b2d424000 RSI: 0000000000400000 RDI: 00007f2c85bb7708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffd5fa6cc40 Showing all locks held in the system: 6 locks held by kworker/u4:0/9: #0: ffff888141580138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff88814d2560e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88814d258c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691 #4: ffff88814d25a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 #5: ffff8880741c8c70 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668 1 lock held by khungtaskd/27: #0: ffffffff8d11efa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3942: #0: ffff88802cd6f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by syz-executor/4173: #0: ffff88807a907828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807a907828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204 #2: ffff88814d25a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 3 locks held by syz.0.1805/9781: #0: ffff88807a901628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807a901628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204 #2: ffff88814d25a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 3 locks held by syz.9.1806/9789: #0: ffff888024cfe328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff888024cfe328 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204 #2: ffff88814d25a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 3 locks held by syz.6.1807/9802: #0: ffff88807b718128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807b718128 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296 #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline] #1: ffff88814d256558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204 #2: ffff88814d25a990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287