syzbot

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BUG: KCSAN: data-race in ext4_setattr / ext4_writepages

write to 0xffff88813a4c11e8 of 8 bytes by task 12617 on cpu 0:
 i_size_write include/linux/fs.h:913 [inline]
 ext4_setattr+0xd7e/0xf20 fs/ext4/inode.c:5440
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate fs/open.c:64 [inline]
 do_sys_ftruncate+0x323/0x430 fs/open.c:192
 __do_sys_ftruncate fs/open.c:203 [inline]
 __se_sys_ftruncate fs/open.c:201 [inline]
 __x64_sys_ftruncate+0x2f/0x40 fs/open.c:201
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813a4c11e8 of 8 bytes by task 12393 on cpu 1:
 i_size_read include/linux/fs.h:891 [inline]
 mpage_submit_page fs/ext4/inode.c:2092 [inline]
 mpage_map_and_submit_buffers fs/ext4/inode.c:2346 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2485 [inline]
 ext4_writepages+0x10b6/0x1e80 fs/ext4/inode.c:2798
 do_writepages+0x1cb/0x330 mm/page-writeback.c:2364
 filemap_fdatawrite_wbc mm/filemap.c:407 [inline]
 __filemap_fdatawrite_range mm/filemap.c:440 [inline]
 __filemap_fdatawrite mm/filemap.c:446 [inline]
 filemap_flush+0xd7/0x100 mm/filemap.c:473
 ext4_alloc_da_blocks+0x47/0x100 fs/ext4/inode.c:3106
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:141
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x160/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000fff000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12393 Comm: syz-executor.5 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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