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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c277e0 of 8 bytes by task 9476 on cpu 0:
 bh_lru_install fs/buffer.c:1230 [inline]
 find_get_block_common+0x45c/0x870 fs/buffer.c:1295
 bdev_getblk+0x4c/0x3c0 include/linux/gfp.h:-1
 __bread_gfp+0x51/0x240 fs/buffer.c:1400
 sb_bread include/linux/buffer_head.h:344 [inline]
 fat__get_entry fs/fat/dir.c:102 [inline]
 fat_get_entry+0x469/0x5d0 fs/fat/dir.c:130
 fat_get_entry_eod fs/fat/dir.c:147 [inline]
 fat_get_short_entry fs/fat/dir.c:913 [inline]
 fat_subdirs+0x59/0x1b0 fs/fat/dir.c:979
 fat_read_root+0x324/0x370 fs/fat/inode.c:1380
 fat_fill_super+0x15a8/0x1c60 fs/fat/inode.c:1862
 msdos_fill_super+0x24/0x30 fs/fat/namei_msdos.c:662
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1872
 get_tree_bdev+0x1f/0x30 fs/super.c:1895
 msdos_get_tree+0x1c/0x30 fs/fat/namei_msdos.c:667
 vfs_get_tree+0x57/0x1d0 fs/super.c:1932
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3848
 path_mount+0x4ad/0xb90 fs/namespace.c:4168
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4374
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4374
 x64_sys_call+0xc3b/0x2550 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c277e0 of 8 bytes by task 8702 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1436
 smp_call_function_many_cond+0x2d1/0xbc0 kernel/smp.c:936
 on_each_cpu_cond_mask+0x35/0x50 kernel/smp.c:1169
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1445
 invalidate_bdev+0x42/0x70 block/bdev.c:99
 ext4_put_super+0x620/0x7c0 fs/ext4/super.c:1357
 generic_shutdown_super+0xee/0x220 fs/super.c:751
 kill_block_super+0x2d/0xb0 fs/super.c:1903
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7527
 deactivate_locked_super+0x73/0x180 fs/super.c:586
 deactivate_super+0x9a/0xb0 fs/super.c:614
 cleanup_mnt+0x2c3/0x340 fs/namespace.c:1317
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1324
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x4a4/0x1510 kernel/exit.c:986
 do_group_exit+0x138/0x140 kernel/exit.c:1129
 __do_sys_exit_group kernel/exit.c:1140 [inline]
 __se_sys_exit_group kernel/exit.c:1138 [inline]
 __x64_sys_exit_group+0x1f/0x20 kernel/exit.c:1138
 x64_sys_call+0x254f/0x2550 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811a2bb420 -> 0xffff88811a1cd9c0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8702 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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