loop6: detected capacity change from 0 to 128
==================================================================
BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c27ce0 of 8 bytes by task 23472 on cpu 0:
 bh_lru_install fs/buffer.c:1234 [inline]
 find_get_block_common+0x457/0x870 fs/buffer.c:1299
 bdev_getblk+0x4b/0x370 fs/buffer.c:-1
 __getblk include/linux/buffer_head.h:436 [inline]
 sb_getblk include/linux/buffer_head.h:442 [inline]
 __ext4_get_inode_loc+0x311/0x970 fs/ext4/inode.c:5738
 ext4_get_inode_loc fs/ext4/inode.c:5866 [inline]
 ext4_reserve_inode_write+0xd7/0x250 fs/ext4/inode.c:7442
 __ext4_mark_inode_dirty+0x87/0x430 fs/ext4/inode.c:7636
 ext4_dirty_inode+0x92/0xc0 fs/ext4/inode.c:7673
 __mark_inode_dirty+0x164/0x700 fs/fs-writeback.c:2741
 generic_update_time fs/inode.c:2252 [inline]
 file_update_time_flags+0x299/0x2d0 fs/inode.c:2482
 file_update_time+0x17/0x20 fs/inode.c:2503
 ext4_page_mkwrite+0x15e/0xc70 fs/ext4/inode.c:7858
 do_page_mkwrite mm/memory.c:3879 [inline]
 do_shared_fault mm/memory.c:6145 [inline]
 do_fault mm/memory.c:6207 [inline]
 do_pte_missing mm/memory.c:4763 [inline]
 handle_pte_fault mm/memory.c:6627 [inline]
 __handle_mm_fault mm/memory.c:6776 [inline]
 handle_mm_fault+0x2701/0x3af0 mm/memory.c:6943
 do_user_addr_fault+0x3ce/0xde0 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595

read to 0xffff888237c27ce0 of 8 bytes by task 23482 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1440
 smp_call_function_many_cond+0x2d1/0xbc0 kernel/smp.c:962
 on_each_cpu_cond_mask+0x35/0x50 kernel/smp.c:1195
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1449
 kill_bdev block/bdev.c:89 [inline]
 set_blocksize+0x1e3/0x270 block/bdev.c:206
 sb_set_blocksize+0x93/0x170 block/bdev.c:239
 fat_fill_super+0x81d/0x1ce0 fs/fat/inode.c:1671
 msdos_fill_super+0x24/0x30 fs/fat/namei_msdos.c:676
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1883
 get_tree_bdev+0x1f/0x30 fs/super.c:1906
 msdos_get_tree+0x1c/0x30 fs/fat/namei_msdos.c:681
 vfs_get_tree+0x57/0x1d0 fs/super.c:1943
 fc_mount fs/namespace.c:1282 [inline]
 do_new_mount_fc fs/namespace.c:3910 [inline]
 do_new_mount+0x288/0x730 fs/namespace.c:3986
 path_mount+0x4ad/0xb90 fs/namespace.c:4337
 do_mount fs/namespace.c:4350 [inline]
 __do_sys_mount fs/namespace.c:4565 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4542
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4542
 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

value changed: 0x0000000000000000 -> 0xffff88810056d4e0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23482 Comm: syz.6.4411 Tainted: G                   Y syzkaller #0 PREEMPT(lazy) 
Tainted: [Y]=FORCED_BIND
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
==================================================================
netlink: 8 bytes leftover after parsing attributes in process `syz.6.4411'.