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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237d27558 of 8 bytes by task 4794 on cpu 1:
 bh_lru_install fs/buffer.c:1345 [inline]
 find_get_block_common+0x4b6/0x8e0 fs/buffer.c:1410
 __getblk_slow fs/buffer.c:-1 [inline]
 bdev_getblk+0x334/0x3f0 fs/buffer.c:1461
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 __ext4_get_inode_loc+0x303/0x930 fs/ext4/inode.c:4835
 __ext4_get_inode_loc_noinmem fs/ext4/inode.c:4948 [inline]
 __ext4_iget+0x2ea/0x2350 fs/ext4/inode.c:5209
 __ext4_fill_super fs/ext4/super.c:5553 [inline]
 ext4_fill_super+0x291d/0x37a0 fs/ext4/super.c:5777
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1691
 get_tree_bdev+0x1f/0x30 fs/super.c:1714
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5809
 vfs_get_tree+0x57/0x1d0 fs/super.c:1751
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount+0x24d/0x6a0 fs/namespace.c:3712
 path_mount+0x4ab/0xb80 fs/namespace.c:4022
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4201
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4201
 x64_sys_call+0x2cca/0x3000 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d27558 of 8 bytes by task 3316 on cpu 0:
 has_bh_in_lru+0x54/0x1f0 fs/buffer.c:1551
 smp_call_function_many_cond+0x2a9/0xc40 kernel/smp.c:821
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1043
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1560
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9a/0x1a0 block/bdev.c:729
 blkdev_put_whole block/bdev.c:736 [inline]
 bdev_release+0x2bf/0x3d0 block/bdev.c:1161
 blkdev_release+0x15/0x20 block/fops.c:706
 __fput+0x29b/0x650 fs/file_table.c:468
 ____fput+0x1c/0x30 fs/file_table.c:496
 task_work_run+0x131/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x1e1/0x2b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff8881097cc000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3316 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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