loop7: detected capacity change from 0 to 512
==================================================================
BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c26f50 of 8 bytes by task 11960 on cpu 0:
 bh_lru_install fs/buffer.c:1345 [inline]
 find_get_block_common+0x4f0/0x960 fs/buffer.c:1410
 __find_get_block_nonatomic fs/buffer.c:1429 [inline]
 bdev_getblk+0x83/0x3b0 fs/buffer.c:1453
 __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:4866
 ext4_get_inode_loc fs/ext4/inode.c:4994 [inline]
 ext4_reserve_inode_write+0xd7/0x250 fs/ext4/inode.c:6323
 __ext4_mark_inode_dirty+0x8c/0x3f0 fs/ext4/inode.c:6501
 ext4_dirty_inode+0x92/0xc0 fs/ext4/inode.c:6538
 __mark_inode_dirty+0x15f/0x750 fs/fs-writeback.c:2527
 generic_update_time fs/inode.c:2063 [inline]
 inode_update_time fs/inode.c:2076 [inline]
 __file_update_time fs/inode.c:2304 [inline]
 file_update_time+0x288/0x2b0 fs/inode.c:2334
 ext4_page_mkwrite+0x18c/0xb90 fs/ext4/inode.c:6704
 do_page_mkwrite mm/memory.c:3361 [inline]
 do_shared_fault mm/memory.c:5649 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x15ce/0x2c20 mm/memory.c:6364
 do_user_addr_fault+0x636/0x1090 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888237c26f50 of 8 bytes by task 11989 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1551
 smp_call_function_many_cond+0x2a9/0xc60 kernel/smp.c:821
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1044
 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]
 set_blocksize+0x24f/0x310 block/bdev.c:207
 sb_set_blocksize+0x7a/0x100 block/bdev.c:224
 fat_fill_super+0xa09/0x1ce0 fs/fat/inode.c:1631
 msdos_fill_super+0x24/0x30 fs/fat/namei_msdos.c:655
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1692
 get_tree_bdev+0x1f/0x30 fs/super.c:1715
 msdos_get_tree+0x1c/0x30 fs/fat/namei_msdos.c:660
 vfs_get_tree+0x57/0x1d0 fs/super.c:1815
 do_new_mount+0x207/0x5e0 fs/namespace.c:3808
 path_mount+0x4a4/0xb20 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4324
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4324
 x64_sys_call+0x2b4d/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811a13f548 -> 0xffff8881045de138

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11989 Comm: syz.7.2456 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================
FAT-fs (loop7): Invalid FSINFO signature: 0x41615252, 0x61000000 (sector = 1)
netlink: 12 bytes leftover after parsing attributes in process `syz.7.2456'.