loop2: detected capacity change from 0 to 512
==================================================================
BUG: KCSAN: data-race in pcpu_alloc_noprof / pcpu_balance_workfn

read-write to 0xffffffff88bdf3ac of 4 bytes by task 35 on cpu 1:
 pcpu_update_empty_pages mm/percpu.c:602 [inline]
 pcpu_chunk_populated mm/percpu.c:1531 [inline]
 pcpu_balance_populated mm/percpu.c:2062 [inline]
 pcpu_balance_workfn+0x94e/0xa60 mm/percpu.c:2212
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffffffff88bdf3ac of 4 bytes by task 3798 on cpu 0:
 pcpu_alloc_noprof+0x9b6/0x10a0 mm/percpu.c:1894
 __percpu_init_rwsem+0x24/0x90 kernel/locking/percpu-rwsem.c:17
 alloc_super+0x19d/0x5b0 fs/super.c:350
 sget_fc+0x259/0x670 fs/super.c:760
 sget_dev fs/super.c:1361 [inline]
 get_tree_bdev+0x137/0x2e0 fs/super.c:1621
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5718
 vfs_get_tree+0x56/0x1e0 fs/super.c:1800
 do_new_mount+0x227/0x690 fs/namespace.c:3507
 path_mount+0x49b/0xb30 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x27c/0x2d0 fs/namespace.c:4034
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4034
 x64_sys_call+0x203e/0x2d60 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: 0x00000001 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3798 Comm: syz.2.100 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================
EXT4-fs error (device loop2): ext4_xattr_ibody_find:2240: inode #15: comm syz.2.100: corrupted in-inode xattr: invalid ea_ino
EXT4-fs error (device loop2): ext4_orphan_get:1393: comm syz.2.100: couldn't read orphan inode 15 (err -117)
EXT4-fs (loop2): mounted filesystem 00000007-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.