INFO: task kworker/u4:1:144 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:22416 pid:  144 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 <TASK>
 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_mb_mark_diskspace_used+0x1c9/0x14e0 fs/ext4/mballoc.c:3871
 ext4_mb_new_blocks+0x11ab/0x47c0 fs/ext4/mballoc.c:5806
 ext4_ext_map_blocks+0x17d1/0x63d0 fs/ext4/extents.c:4372
 ext4_map_blocks+0x97f/0x1a50 fs/ext4/inode.c:675
 mpage_map_one_extent fs/ext4/inode.c:2410 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2463 [inline]
 ext4_writepages+0x124a/0x2d40 fs/ext4/inode.c:2831
 do_writepages+0x493/0x700 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940
 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011
 wb_writeback+0x45e/0xbc0 fs/fs-writeback.c:2116
 wb_check_old_data_flush fs/fs-writeback.c:2216 [inline]
 wb_do_writeback fs/fs-writeback.c:2269 [inline]
 wb_workfn+0xb15/0xf20 fs/fs-writeback.c:2298
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task jbd2/sda1-8:3521 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jbd2/sda1-8     state:D stack:25392 pid: 3521 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 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_buffer include/linux/buffer_head.h:390 [inline]
 jbd2_journal_commit_transaction+0x2f0b/0x5c30 fs/jbd2/commit.c:848
 kjournald2+0x45a/0x900 fs/jbd2/journal.c:213
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task syz-executor:4174 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23104 pid: 4174 ppid:  4173 flags:0x00004002
Call Trace:
 <TASK>
 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: 0033:0x7f4c4305c1e3
RSP: 002b:00007ffe2f2fd510 EFLAGS: 00010202
RAX: 00007f4c40bec000 RBX: 00007ffe2f2fd640 RCX: 0000000000dffde8
RDX: 00007f4c40bebffc RSI: 0000000000000008 RDI: 00007ffe2f2fd640
RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffe2f2fd620 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
INFO: task syz.4.144:4640 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.144       state:D stack:27440 pid: 4640 ppid:  4190 flags:0x00004004
Call Trace:
 <TASK>
 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: 0033:0x7fd6e8da1809
RSP: 002b:00007fff17852690 EFLAGS: 00010202
RAX: 0000001b32924000 RBX: 0000000000000000 RCX: 00000000003ffde8
RDX: 0000001b32923ffc RSI: 00000000003ffde8 RDI: 00007fd6e9c84700
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fd6e9141000
R10: 00007fd6e9c84700 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000640 R14: ffffffff819d64d4 R15: 00007fd6e9c84720
 </TASK>
INFO: task syz.1.145:4644 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.145       state:D stack:27696 pid: 4644 ppid:  4187 flags:0x00004004
Call Trace:
 <TASK>
 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: 0033:0x7fbb1881aaa3
RSP: 002b:00007ffffa0e4840 EFLAGS: 00010246
RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b32264000
RDX: 0000001b32224000 RSI: 0000000000400000 RDI: 00007fbb18b8f708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffffa0e4ad0
 </TASK>
INFO: task syz.3.146:4645 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.146       state:D stack:26272 pid: 4645 ppid:  4186 flags:0x00004004
Call Trace:
 <TASK>
 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: 0033:0x7fa661a42aa3
RSP: 002b:00007ffcf068e060 EFLAGS: 00010246
RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b32464000
RDX: 0000001b32424000 RSI: 0000000000400000 RDI: 00007fa661db7708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffcf068e2f0
 </TASK>
INFO: task syz.2.147:4646 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.147       state:D stack:27696 pid: 4646 ppid:  4189 flags:0x00004004
Call Trace:
 <TASK>
 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: 0033:0x7f2e003eaaa3
RSP: 002b:00007ffe4c558770 EFLAGS: 00010246
RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000001b32364000
RDX: 0000001b32324000 RSI: 0000000000400000 RDI: 00007f2e0075f708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe4c558a00
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
6 locks held by kworker/u4:1/144:
 #0: ffff888019df8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900016efd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff88807f6820e0 (&type->s_umount_key#32){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418
 #3: ffff88807f684c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
 #4: ffff88807f686990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
 #5: ffff888079cb4840 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668
2 locks held by getty/3942:
 #0: ffff88802c156098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
3 locks held by syz-executor/4174:
 #0: ffff88807dfee328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x50 include/linux/mmap_lock.h:117
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88807f686990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
2 locks held by kworker/1:6/4234:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900031afd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by syz.4.144/4640:
 #0: ffff88807dfef828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807dfef828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88807f686990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
3 locks held by syz.1.145/4644:
 #0: ffff88807d605c28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807d605c28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88807f686990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
3 locks held by syz.3.146/4645:
 #0: ffff88807b10e328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807b10e328 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88807f686990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
3 locks held by syz.2.147/4646:
 #0: ffff88807b108128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807b108128 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2bb/0xc90 arch/x86/mm/fault.c:1296
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1817 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1916 [inline]
 #1: ffff88807f682558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6204
 #2: ffff88807f686990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12d5/0x1560 fs/jbd2/transaction.c:462
2 locks held by dhcpcd/4931:
 #0: ffff88804fbe8120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff88804fbe8120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3243
 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845

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

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:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:unwind_next_frame+0x664/0x1cf0 arch/x86/kernel/unwind_orc.c:475
Code: 00 00 4c 8d 73 40 4c 89 f0 48 c1 e8 03 80 3c 28 00 74 08 4c 89 f7 e8 cb 23 89 00 49 8b 16 4d 8d 7c 24 01 4c 89 e0 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 d0 12 00 00 4c 89 f8 48 c1 e8 03 0f b6 04
RSP: 0018:ffffc90000ce6ef0 EFLAGS: 00000a07
RAX: 1ffffffff1d20774 RBX: ffffc90000ce6f88 RCX: ffffffff8df62fec
RDX: ffffc90000ce7950 RSI: ffffffff8df62fe8 RDI: 0000000000000001
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000006
R10: dffffc0000000000 R11: fffff5200019cdfd R12: ffffffff8e903ba6
R13: 1ffffffff1d20775 R14: ffffc90000ce6fc8 R15: ffffffff8e903ba7
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd150bd300 CR3: 000000002af45000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 kvfree_call_rcu+0x105/0x7f0 kernel/rcu/tree.c:3600
 cfg80211_update_known_bss+0x184/0xb60 net/wireless/scan.c:-1
 cfg80211_bss_update+0x156/0x21a0 net/wireless/scan.c:1830
 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2552 [inline]
 cfg80211_inform_bss_frame_data+0x88d/0x1ed0 net/wireless/scan.c:2585
 ieee80211_bss_info_update+0x6ba/0xa80 net/mac80211/scan.c:190
 ieee80211_rx_bss_info net/mac80211/ibss.c:1123 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1614 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1763/0x2b50 net/mac80211/ibss.c:1643
 ieee80211_iface_process_skb net/mac80211/iface.c:1465 [inline]
 ieee80211_iface_work+0x714/0xc50 net/mac80211/iface.c:1519
 cfg80211_wiphy_work+0x224/0x260 net/wireless/core.c:433
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>