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BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

read-write to 0xffff888237c2ba28 of 8 bytes by task 7051 on cpu 0:
 bh_lru_install fs/buffer.c:1337 [inline]
 __find_get_block+0x434/0x8a0 fs/buffer.c:1400
 bdev_getblk+0x30/0x3b0 fs/buffer.c:1425
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 __ext4_get_inode_loc+0x2f7/0x910 fs/ext4/inode.c:4440
 ext4_get_inode_loc fs/ext4/inode.c:4568 [inline]
 ext4_reserve_inode_write+0xb0/0x200 fs/ext4/inode.c:5827
 __ext4_mark_inode_dirty+0x8e/0x440 fs/ext4/inode.c:6004
 ext4_write_end+0x34f/0x770 fs/ext4/inode.c:1328
 generic_perform_write+0x33c/0x4a0 mm/filemap.c:4070
 ext4_buffered_write_iter+0x1ea/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x383/0xf20
 iter_file_splice_write+0x5f1/0x980 fs/splice.c:743
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x160/0x2c0 fs/splice.c:1164
 splice_direct_to_actor+0x302/0x670 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x398/0x660 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64 fs/read_write.c:1410 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1410
 x64_sys_call+0xfbd/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c2ba28 of 8 bytes by task 3327 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1521
 cpu_needs_drain mm/swap.c:748 [inline]
 __lru_add_drain_all+0x23f/0x3f0 mm/swap.c:835
 lru_add_drain_all+0x10/0x20 mm/swap.c:851
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x571/0x840 fs/ext4/super.c:1356
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7379
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x268/0x2e0 fs/namespace.c:1373
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1380
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888106740548

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3327 Comm: syz-executor Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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