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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c275e0 of 8 bytes by task 4385 on cpu 0:
 bh_lru_install fs/buffer.c:1323 [inline]
 find_get_block_common+0x45c/0x870 fs/buffer.c:1388
 bdev_getblk+0x4c/0x3c0 include/linux/gfp.h:-1
 ext4_sb_breadahead_unmovable+0x45/0x170 fs/ext4/super.c:280
 __ext4_get_inode_loc+0x723/0x930 fs/ext4/inode.c:4974
 __ext4_get_inode_loc_noinmem fs/ext4/inode.c:5004 [inline]
 __ext4_iget+0x2f4/0x2400 fs/ext4/inode.c:5316
 __ext4_fill_super fs/ext4/super.c:5600 [inline]
 ext4_fill_super+0x28be/0x3760 fs/ext4/super.c:5828
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1634
 get_tree_bdev+0x1f/0x30 fs/super.c:1657
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5860
 vfs_get_tree+0x57/0x1d0 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3841
 path_mount+0x4ad/0xb90 fs/namespace.c:4161
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4367
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4367
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c275e0 of 8 bytes by task 3296 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1529
 smp_call_function_many_cond+0x297/0xb60 kernel/smp.c:836
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1057
 on_each_cpu_cond include/linux/smp.h:106 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1538
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x94/0x1a0 block/bdev.c:715
 blkdev_put_whole block/bdev.c:722 [inline]
 bdev_release+0x2c1/0x3d0 block/bdev.c:1147
 blkdev_release+0x15/0x20 block/fops.c:680
 __fput+0x29e/0x630 fs/file_table.c:512
 ____fput+0x1c/0x30 fs/file_table.c:540
 task_work_run+0x130/0x1a0 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:70 [inline]
 exit_to_user_mode_loop+0x1e4/0x8c0 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x23c/0x3c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888105ad6780 -> 0xffff888105ad6540

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3296 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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