loop4: detected capacity change from 0 to 512
==================================================================
BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

read-write to 0xffff888237c2ba28 of 8 bytes by task 3292 on cpu 0:
 bh_lru_install fs/buffer.c:1337 [inline]
 __find_get_block+0x42e/0x890 fs/buffer.c:1400
 bdev_getblk+0x30/0x3b0 fs/buffer.c:1425
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 __ext4_get_inode_loc+0x2f7/0x940 fs/ext4/inode.c:4440
 ext4_get_inode_loc fs/ext4/inode.c:4568 [inline]
 ext4_reserve_inode_write+0xb0/0x200 fs/ext4/inode.c:5828
 __ext4_mark_inode_dirty+0x8e/0x440 fs/ext4/inode.c:6005
 ext4_dirty_inode+0x91/0xb0 fs/ext4/inode.c:6042
 __mark_inode_dirty+0x166/0x7e0 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:2112 [inline]
 inode_update_time fs/inode.c:2125 [inline]
 __file_update_time fs/inode.c:2353 [inline]
 file_update_time+0x285/0x2b0 fs/inode.c:2383
 ext4_page_mkwrite+0x19e/0xb70 fs/ext4/inode.c:6160
 do_page_mkwrite mm/memory.c:3255 [inline]
 wp_page_shared mm/memory.c:3656 [inline]
 do_wp_page+0xca1/0x2340 mm/memory.c:3806
 handle_pte_fault mm/memory.c:5916 [inline]
 __handle_mm_fault mm/memory.c:6043 [inline]
 handle_mm_fault+0xc63/0x2ac0 mm/memory.c:6212
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x3b9/0x650 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888237c2ba28 of 8 bytes by task 6110 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1521
 smp_call_function_many_cond+0x305/0xbb0 kernel/smp.c:838
 on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1052
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1530
 kill_bdev block/bdev.c:90 [inline]
 set_blocksize+0x24f/0x270 block/bdev.c:172
 sb_set_blocksize+0x2c/0xb0 block/bdev.c:181
 ext4_load_super fs/ext4/super.c:5096 [inline]
 __ext4_fill_super fs/ext4/super.c:5248 [inline]
 ext4_fill_super+0x12d9/0x3630 fs/ext4/super.c:5722
 get_tree_bdev_flags+0x29f/0x310 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5754
 vfs_get_tree+0x56/0x1e0 fs/super.c:1814
 do_new_mount+0x227/0x690 fs/namespace.c:3560
 path_mount+0x49b/0xb30 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:4088
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4088
 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff8881060af068

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6110 Comm: syz.4.825 Not tainted 6.14.0-rc5-syzkaller-00234-gb7c90e3e717a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
EXT4-fs (loop4): 1 orphan inode deleted
EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
ext4 filesystem being mounted at /176/file1 supports timestamps until 2038-01-19 (0x7fffffff)