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BUG: KCSAN: data-race in inode_needs_update_time / inode_update_timestamps

write to 0xffff888100562aa8 of 8 bytes by task 22404 on cpu 0:
 inode_update_timestamps+0x389/0x530 fs/inode.c:1896
 generic_update_time fs/inode.c:1929 [inline]
 inode_update_time fs/inode.c:1949 [inline]
 __file_update_time fs/inode.c:2135 [inline]
 file_modified_flags+0x144/0x1d0 fs/inode.c:2206
 file_modified+0x17/0x20 fs/inode.c:2222
 ext4_write_checks fs/ext4/file.c:279 [inline]
 ext4_buffered_write_iter+0x1d8/0x370 fs/ext4/file.c:295
 ext4_file_write_iter+0xd6/0x1200
 call_write_iter include/linux/fs.h:1956 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4ab/0x7d0 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888100562aa8 of 8 bytes by task 22402 on cpu 1:
 timespec64_equal include/linux/time64.h:49 [inline]
 inode_needs_update_time+0x1c0/0x2f0 fs/inode.c:2115
 file_update_time+0x2d/0x140 fs/inode.c:2161
 ext4_page_mkwrite+0x1a4/0xb70 fs/ext4/inode.c:6074
 do_page_mkwrite mm/memory.c:2931 [inline]
 wp_page_shared mm/memory.c:3291 [inline]
 do_wp_page+0xcab/0x1ee0 mm/memory.c:3376
 handle_pte_fault mm/memory.c:4994 [inline]
 __handle_mm_fault mm/memory.c:5119 [inline]
 handle_mm_fault+0xe2a/0x2cc0 mm/memory.c:5284
 do_user_addr_fault arch/x86/mm/fault.c:1413 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x2f7/0x6c0 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
 __put_user_4+0x11/0x20 arch/x86/lib/putuser.S:87
 ioctl_fibmap fs/ioctl.c:91 [inline]
 file_ioctl fs/ioctl.c:328 [inline]
 do_vfs_ioctl+0x132a/0x13a0 fs/ioctl.c:850
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0x81/0x140 fs/ioctl.c:857
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000013928e76 -> 0x00000000142b24f6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22402 Comm: syz-executor.4 Not tainted 6.6.0-rc4-syzkaller-00229-g82714078aee4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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