loop7: detected capacity change from 0 to 256
==================================================================
BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c277a0 of 8 bytes by task 21598 on cpu 0:
 bh_lru_install fs/buffer.c:1242 [inline]
 find_get_block_common+0x459/0x870 fs/buffer.c:1307
 bdev_getblk+0x4d/0x3f0 include/linux/gfp.h:-1
 __bread_gfp+0x51/0x240 fs/buffer.c:1412
 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_scan+0x103/0x200 fs/fat/dir.c:973
 vfat_find_form fs/fat/namei_vfat.c:237 [inline]
 vfat_create_shortname fs/fat/namei_vfat.c:446 [inline]
 vfat_build_slots fs/fat/namei_vfat.c:609 [inline]
 vfat_add_entry+0x1372/0x2280 fs/fat/namei_vfat.c:670
 vfat_create+0xb1/0x1b0 fs/fat/namei_vfat.c:769
 lookup_open fs/namei.c:4511 [inline]
 open_last_lookups fs/namei.c:4611 [inline]
 path_openat+0xd75/0x2050 fs/namei.c:4855
 do_file_open+0x16c/0x290 fs/namei.c:4887
 do_sys_openat2+0x94/0x130 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_open fs/open.c:1378 [inline]
 __se_sys_open fs/open.c:1374 [inline]
 __x64_sys_open+0xe6/0x110 fs/open.c:1374
 x64_sys_call+0x14b9/0x3020 arch/x86/include/generated/asm/syscalls_64.h:3
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c277a0 of 8 bytes by task 21610 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1448
 smp_call_function_many_cond+0x2a7/0xb70 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:1457
 kill_bdev block/bdev.c:90 [inline]
 set_blocksize+0x1e3/0x270 block/bdev.c:207
 sb_set_blocksize+0x93/0x170 block/bdev.c:240
 fat_fill_super+0x842/0x1c10 fs/fat/inode.c:1639
 vfat_fill_super+0x24/0x30 fs/fat/namei_vfat.c:1202
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 vfat_get_tree+0x1c/0x30 fs/fat/namei_vfat.c:1207
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3834
 path_mount+0x4d0/0xbc0 fs/namespace.c:4154
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360
 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/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811ad142d8 -> 0xffff888107a00340

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 21610 Comm: syz.7.3747 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
==================================================================
FAT-fs (loop7): Invalid FSINFO signature: 0x00fffff8, 0x00000000 (sector = 1)