syzbot

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BUG: KCSAN: data-race in __mark_inode_dirty / redirty_tail_locked

read-write to 0xffff888109c92640 of 8 bytes by task 3546 on cpu 1:
 redirty_tail_locked+0x56/0x270 fs/fs-writeback.c:1305
 requeue_inode fs/fs-writeback.c:1561 [inline]
 writeback_sb_inodes+0x7b2/0xaa0 fs/fs-writeback.c:1923
 wb_writeback+0x252/0x6e0 fs/fs-writeback.c:2070
 wb_do_writeback fs/fs-writeback.c:2217 [inline]
 wb_workfn+0x1a8/0x8d0 fs/fs-writeback.c:2257
 process_one_work+0x434/0x860 kernel/workqueue.c:2600
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2751
 kthread+0x1d7/0x210 kernel/kthread.c:389
 ret_from_fork+0x2e/0x40 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

read to 0xffff888109c92640 of 8 bytes by task 4176 on cpu 0:
 __mark_inode_dirty+0x199/0x7d0 fs/fs-writeback.c:2452
 mark_buffer_dirty+0x165/0x240 fs/buffer.c:1221
 __block_commit_write fs/buffer.c:2202 [inline]
 block_write_end+0x158/0x2e0 fs/buffer.c:2280
 generic_write_end+0x61/0x240 fs/buffer.c:2294
 ext4_da_write_end+0x49e/0x700 fs/ext4/inode.c:2988
 generic_perform_write+0x26d/0x410 mm/filemap.c:3934
 ext4_buffered_write_iter+0x1f6/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x283/0x1230
 __kernel_write_iter+0x162/0x3c0 fs/read_write.c:517
 dump_emit_page fs/coredump.c:888 [inline]
 dump_user_range+0x25d/0x490 fs/coredump.c:915
 elf_core_dump+0x1a85/0x1ba0 fs/binfmt_elf.c:2142
 do_coredump+0x1029/0x1890 fs/coredump.c:764
 get_signal+0xd65/0xff0 kernel/signal.c:2867
 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:308
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:310
 irqentry_exit+0x12/0x40 kernel/entry/common.c:413
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

value changed: 0x0000000000020084 -> 0x0000000000000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4176 Comm: syz-executor.4 Not tainted 6.5.0-rc7-syzkaller-00024-g93f5de5f648d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
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syz-executor.4 (4176) used greatest stack depth: 10296 bytes left