loop8: detected capacity change from 0 to 512
EXT4-fs: Ignoring removed nobh option
EXT4-fs (loop8): blocks per group (95) and clusters per group (32768) inconsistent
==================================================================
BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

read-write to 0xffff888237d26b30 of 8 bytes by task 10552 on cpu 1:
 bh_lru_install fs/buffer.c:1337 [inline]
 __find_get_block+0x430/0x8a0 fs/buffer.c:1400
 bdev_getblk+0x30/0x3b0 fs/buffer.c:1425
 __bread_gfp+0x52/0x280 fs/buffer.c:1485
 sb_bread include/linux/buffer_head.h:345 [inline]
 __fat_write_inode+0x159/0x580 fs/fat/inode.c:871
 fat_write_inode+0xbd/0xd0 fs/fat/inode.c:922
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x340/0x850 fs/fs-writeback.c:1745
 writeback_single_inode+0x16c/0x3f0 fs/fs-writeback.c:1801
 sync_inode_metadata+0x60/0x90 fs/fs-writeback.c:2883
 __generic_file_fsync+0xed/0x140 fs/libfs.c:1536
 fat_file_fsync+0x46/0x100 fs/fat/file.c:191
 vfs_fsync_range+0x116/0x130 fs/sync.c:187
 generic_write_sync include/linux/fs.h:2976 [inline]
 generic_file_write_iter+0x1cc/0x310 mm/filemap.c:4249
 iter_file_splice_write+0x5f2/0x980 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x160/0x2c0 fs/splice.c:1158
 splice_direct_to_actor+0x305/0x680 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d26b30 of 8 bytes by task 10584 on cpu 0:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1521
 cpu_needs_drain mm/swap.c:780 [inline]
 __lru_add_drain_all+0x23f/0x3f0 mm/swap.c:867
 lru_add_drain_all+0x10/0x20 mm/swap.c:883
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 __ext4_fill_super fs/ext4/super.c:5701 [inline]
 ext4_fill_super+0x1551/0x3580 fs/ext4/super.c:5726
 get_tree_bdev_flags+0x2b4/0x330 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5758
 vfs_get_tree+0x56/0x1e0 fs/super.c:1759
 do_new_mount+0x246/0x6b0 fs/namespace.c:3879
 path_mount+0x49b/0xb30 fs/namespace.c:4206
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4407
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4407
 x64_sys_call+0xd11/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888106620e38

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10584 Comm: syz.8.2615 Not tainted 6.14.0-syzkaller-13423-ga8662bcd2ff1 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
IPv6: Can't replace route, no match found