INFO: task jbd2/sda1-8:3605 blocked 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:25872 pid:3605  ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x1089/0x4140 kernel/sched/core.c:6584
 schedule+0xb9/0x180 kernel/sched/core.c:6660
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8848
 bit_wait_io+0xf/0x100 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_buffer include/linux/buffer_head.h:385 [inline]
 jbd2_journal_commit_transaction+0x2f0f/0x5f30 fs/jbd2/commit.c:849
 kjournald2+0x40b/0x800 fs/jbd2/journal.c:210
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task syz-executor:4262 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:22992 pid:4262  ppid:4261   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x1089/0x4140 kernel/sched/core.c:6584
 schedule+0xb9/0x180 kernel/sched/core.c:6660
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8848
 bit_wait_io+0xf/0x100 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:5978
 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6162
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6199
 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:1944 [inline]
 inode_update_time fs/inode.c:1957 [inline]
 __file_update_time+0x21d/0x240 fs/inode.c:2145
 file_update_time+0x2f3/0x370 fs/inode.c:2176
 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6317
 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+0x5a9/0xbb0 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: 0033:0x7f300f071a63
RSP: 002b:00007ffd5601ffb0 EFLAGS: 00010212
RAX: 00007f30091fc634 RBX: 00007ffd560200e0 RCX: 0000000000000000
RDX: 00007f30091fc630 RSI: 0000000000000008 RDI: 00007ffd560200e0
RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffd560200c0 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000039cc R14: ffffffffffffc634 R15: 0000000000000000
 </TASK>
INFO: task syz.5.1577:8561 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.1577      state:D stack:25360 pid:8561  ppid:6437   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x1089/0x4140 kernel/sched/core.c:6584
 schedule+0xb9/0x180 kernel/sched/core.c:6660
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8848
 bit_wait_io+0xf/0x100 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:5978
 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6162
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6199
 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:1944 [inline]
 inode_update_time fs/inode.c:1957 [inline]
 __file_update_time+0x21d/0x240 fs/inode.c:2145
 file_update_time+0x2f3/0x370 fs/inode.c:2176
 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6317
 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+0x5a9/0xbb0 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: 0033:0x7f768ee6c7c3
RSP: 002b:00007ffd70637a40 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2d264000
RDX: 0000001b2d224000 RSI: 0000000000600000 RDI: 00007f768f1e8708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffd70637cd0
 </TASK>
INFO: task syz.1.1579:8562 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1579      state:D stack:25360 pid:8562  ppid:4275   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x1089/0x4140 kernel/sched/core.c:6584
 schedule+0xb9/0x180 kernel/sched/core.c:6660
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8848
 bit_wait_io+0xf/0x100 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:5978
 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6162
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6199
 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:1944 [inline]
 inode_update_time fs/inode.c:1957 [inline]
 __file_update_time+0x21d/0x240 fs/inode.c:2145
 file_update_time+0x2f3/0x370 fs/inode.c:2176
 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6317
 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+0x5a9/0xbb0 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: 0033:0x7f668ce6c7c3
RSP: 002b:00007ffde91b30a0 EFLAGS: 00010246
RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b2fb64000
RDX: 0000001b2fb24000 RSI: 0000000000400000 RDI: 00007f668d1e8708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffde91b3330
 </TASK>
INFO: task syz.0.1578:8563 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1578      state:D stack:25360 pid:8563  ppid:4279   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x1089/0x4140 kernel/sched/core.c:6584
 schedule+0xb9/0x180 kernel/sched/core.c:6660
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8848
 bit_wait_io+0xf/0x100 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:5978
 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6162
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6199
 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:1944 [inline]
 inode_update_time fs/inode.c:1957 [inline]
 __file_update_time+0x21d/0x240 fs/inode.c:2145
 file_update_time+0x2f3/0x370 fs/inode.c:2176
 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6317
 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+0x5a9/0xbb0 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: 0033:0x7f4e51c6c7c3
RSP: 002b:00007ffd0961fd50 EFLAGS: 00010246
RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b2fa64000
RDX: 0000001b2fa24000 RSI: 0000000000400000 RDI: 00007f4e51fe8708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffd0961ffe0
 </TASK>
INFO: task syz.3.1581:8564 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1581      state:D stack:25360 pid:8564  ppid:4288   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5257 [inline]
 __schedule+0x1089/0x4140 kernel/sched/core.c:6584
 schedule+0xb9/0x180 kernel/sched/core.c:6660
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8848
 bit_wait_io+0xf/0x100 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:5978
 __ext4_mark_inode_dirty+0x161/0x7b0 fs/ext4/inode.c:6162
 ext4_dirty_inode+0xbf/0x100 fs/ext4/inode.c:6199
 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:1944 [inline]
 inode_update_time fs/inode.c:1957 [inline]
 __file_update_time+0x21d/0x240 fs/inode.c:2145
 file_update_time+0x2f3/0x370 fs/inode.c:2176
 ext4_page_mkwrite+0x1a9/0x10d0 fs/ext4/inode.c:6317
 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+0x5a9/0xbb0 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: 0033:0x7f21d566c7c3
RSP: 002b:00007ffef83cb1b0 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2fd64000
RDX: 0000001b2fd24000 RSI: 0000000000600000 RDI: 00007f21d59e8708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffef83cb440
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8db2e3f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xce0 kernel/rcu/tasks.h:543
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8db2ec30 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xce0 kernel/rcu/tasks.h:543
1 lock held by khungtaskd/28:
 #0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
6 locks held by kworker/u4:2/31:
 #0: ffff88801d254938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000a7fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #2: ffff88814e01c0e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
 #3: ffff88814e01ec18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1785 [inline]
 #3: ffff88814e01ec18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x246/0x2fe0 fs/ext4/inode.c:2719
 #4: ffff88814d9ee990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463
 #5: ffff888070009698 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674
2 locks held by getty/4029:
 #0: ffff88803118f098 (&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+0x430/0x1400 drivers/tty/n_tty.c:2198
3 locks held by syz-executor/4262:
 #0: ffff888078cb88d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888078cb88d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline]
 #0: ffff888078cb88d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6316
 #2: ffff88814d9ee990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463
3 locks held by syz.5.1577/8561:
 #0: ffff88807dcaae58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807dcaae58 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline]
 #0: ffff88807dcaae58 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6316
 #2: ffff88814d9ee990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463
3 locks held by syz.1.1579/8562:
 #0: ffff88807dac97d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807dac97d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline]
 #0: ffff88807dac97d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6316
 #2: ffff88814d9ee990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463
3 locks held by syz.0.1578/8563:
 #0: ffff88807daca6d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807daca6d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline]
 #0: ffff88807daca6d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6316
 #2: ffff88814d9ee990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463
3 locks held by syz.3.1581/8564:
 #0: ffff88807dacf958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807dacf958 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline]
 #0: ffff88807dacf958 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1897 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:2001 [inline]
 #1: ffff88814e01c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6316
 #2: ffff88814d9ee990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x2014/0x2240 fs/jbd2/transaction.c:463

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:230
Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <c3> 0f 1f 80 00 00 00 00 48 8b 04 24 65 48 8b 15 34 06 80 7e 65 8b
RSP: 0018:ffffc900000e76b8 EFLAGS: 00000293
RAX: ffffffff81d401f7 RBX: ffff88823bc8d000 RCX: ffff888018708000
RDX: 0000000000000000 RSI: ffff88823bc8d000 RDI: ffff88823bc8c0f0
RBP: ffffc900000e77f0 R08: ffffea0008ef2307 R09: 1ffffd40011de460
R10: dffffc0000000000 R11: fffff940011de461 R12: dffffc0000000000
R13: 0000000000000a20 R14: ffff88823bc8c0f1 R15: ffff888142244500
FS:  0000000000000000(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555bf3b660 CR3: 000000000d88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 for_each_canary mm/kfence/core.c:351 [inline]
 kfence_guarded_alloc+0x8d7/0xe50 mm/kfence/core.c:440
 __kfence_alloc+0x396/0x3d0 mm/kfence/core.c:1083
 kfence_alloc include/linux/kfence.h:128 [inline]
 slab_alloc_node mm/slub.c:3290 [inline]
 kmem_cache_alloc_node+0x2a4/0x310 mm/slub.c:3411
 __alloc_skb+0xf9/0x7d0 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1303 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x24f/0xa80 drivers/net/netdevsim/dev.c:851
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>