INFO: task syz-executor:4259 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:22656 pid:4259 ppid:4258 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 wp_page_shared+0x167/0x370 mm/memory.c:3358 handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f9463a715e3 RSP: 002b:00007ffe548f9640 EFLAGS: 00010202 RAX: 00007f9460800000 RBX: 00007ffe548f9770 RCX: 00000000005ffde8 RDX: 00007f94607ffffc RSI: 0000000000000008 RDI: 00007ffe548f9770 RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffe548f9750 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.9.7280:25053 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.7280 state:D stack:25488 pid:25053 ppid:16106 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x199c/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f6865c73c09 RSP: 002b:00007ffd47b1c720 EFLAGS: 00010202 RAX: 0000001b32024000 RBX: 0000000000000000 RCX: 00000000005ffde8 RDX: 0000001b32023ffc RSI: 00000000005ffde8 RDI: 00007f6866b55700 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f6866012000 R10: 00007f6866b55700 R11: 0000000000000001 R12: 0000000000000000 R13: 000000000000068a R14: ffffffff812f8a4c R15: 00007f6866b55720 INFO: task syz.1.7285:25068 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.7285 state:D stack:27600 pid:25068 ppid:16443 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x199c/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f68b666cea3 RSP: 002b:00007fff7e624bf0 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2f164000 RDX: 0000001b2f124000 RSI: 0000000000600000 RDI: 00007f68b69e7708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007fff7e624e80 INFO: task syz.6.7286:25069 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.7286 state:D stack:27600 pid:25069 ppid:17423 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0x9b/0x2c0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] do_get_write_access+0x605/0xf20 fs/jbd2/transaction.c:1115 jbd2_journal_get_write_access+0x108/0x140 fs/jbd2/transaction.c:1250 __ext4_journal_get_write_access+0x24b/0x6e0 fs/ext4/ext4_jbd2.c:235 ext4_reserve_inode_write+0x201/0x290 fs/ext4/inode.c:5945 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6129 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6166 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515 generic_update_time fs/inode.c:1946 [inline] inode_update_time fs/inode.c:1959 [inline] __file_update_time+0x21d/0x240 fs/inode.c:2147 file_update_time+0x2f3/0x370 fs/inode.c:2178 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6284 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x199c/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fd677c6cea3 RSP: 002b:00007fffccf45270 EFLAGS: 00010246 RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b34464000 RDX: 0000001b34424000 RSI: 0000000000600000 RDI: 00007fd677fe7708 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00007fffccf45500 Showing all locks held in the system: 4 locks held by kworker/u4:1/11: #0: ffff888140ad8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffff88814dc940e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415 #3: ffff88814dc96c18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d92e230 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d92ea50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669 2 locks held by getty/4028: #0: ffff88807e148098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 3 locks held by syz-executor/4259: #0: ffff888073b93d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff888073b93d58 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff888073b93d58 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88814dc98990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 2 locks held by kworker/u4:8/4370: #0: ffff8880b8c3acd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:538 #1: ffff8880b8c27888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x400/0x740 kernel/sched/psi.c:999 3 locks held by syz.9.7280/25053: #0: ffff8880305f97d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff8880305f97d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff8880305f97d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88814dc98990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 3 locks held by syz.1.7285/25068: #0: ffff88807e169058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807e169058 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff88807e169058 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88814dc98990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 3 locks held by syz.6.7286/25069: #0: ffff88807e16bd58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807e16bd58 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff88807e16bd58 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline] #1: ffff88814dc94558 (sb_pagefaults){++++}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6283 #2: ffff88814dc98990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463 ============================================= 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 09/16/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295