EXT4-fs (loop6): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c27760 of 8 bytes by task 14283 on cpu 0:
 bh_lru_install fs/buffer.c:1342 [inline]
 find_get_block_common+0x459/0x8a0 fs/buffer.c:1407
 bdev_getblk+0x4d/0x3f0 include/linux/gfp.h:-1
 __bread_gfp+0x51/0x240 fs/buffer.c:1512
 sb_bread include/linux/buffer_head.h:346 [inline]
 fat__get_entry fs/fat/dir.c:102 [inline]
 fat_get_entry+0x46e/0x5d0 fs/fat/dir.c:130
 fat_get_short_entry fs/fat/dir.c:888 [inline]
 fat_subdirs+0xf6/0x190 fs/fat/dir.c:954
 fat_read_root+0x316/0x360 fs/fat/inode.c:1348
 fat_fill_super+0x14c8/0x1c10 fs/fat/inode.c:1821
 msdos_fill_super+0x24/0x30 fs/fat/namei_msdos.c:657
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 msdos_get_tree+0x1c/0x30 fs/fat/namei_msdos.c:662
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3839
 path_mount+0x4d0/0xbc0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4338
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4338
 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+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c27760 of 8 bytes by task 8137 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1548
 smp_call_function_many_cond+0x2c1/0xc30 kernel/smp.c:821
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1043
 on_each_cpu_cond include/linux/smp.h:106 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1557
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9a/0x1a0 block/bdev.c:728
 blkdev_put_whole block/bdev.c:735 [inline]
 bdev_release+0x2bf/0x3d0 block/bdev.c:1160
 blkdev_release+0x15/0x20 block/fops.c:705
 __fput+0x29b/0x650 fs/file_table.c:469
 ____fput+0x1c/0x30 fs/file_table.c:497
 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:67 [inline]
 exit_to_user_mode_loop+0x1f4/0x6f0 kernel/entry/common.c:98
 __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 include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x249/0x370 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811bb7e888 -> 0xffff88814110ee38

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8137 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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