loop1: detected capacity change from 0 to 512
EXT4-fs (loop1): 1 orphan inode deleted
==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff86882d70 of 8 bytes by task 12295 on cpu 1:
 data_alloc+0x27d/0x2b0 kernel/printk/printk_ringbuffer.c:1096
 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 __ext4_error+0x248/0x320 fs/ext4/super.c:813
 ext4_release_dquot+0x2e7/0x460 fs/ext4/super.c:6967
 quota_release_workfn+0x256/0x530 fs/quota/dquot.c:840
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86882d70 of 8 bytes by task 15043 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline]
 prb_reserve+0x221/0xaf0 kernel/printk/printk_ringbuffer.c:1619
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 mnt_warn_timestamp_expiry+0x1c3/0x200 fs/namespace.c:3265
 do_new_mount_fc fs/namespace.c:3791 [inline]
 do_new_mount+0x2f6/0x680 fs/namespace.c:3858
 path_mount+0x4a4/0xb20 fs/namespace.c:4180
 do_mount fs/namespace.c:4193 [inline]
 __do_sys_mount fs/namespace.c:4404 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4381
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4381
 x64_sys_call+0xd36/0x2fb0 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: 0x0000000000012818 -> 0x00000000000af648

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 15043 Comm: syz.1.3956 Not tainted 6.15.0-syzkaller-12141-gec7714e49479 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
ext4 filesystem being mounted at /341/file0 supports timestamps until 2038-01-19 (0x7fffffff)
EXT4-fs error (device loop1): ext4_lookup:1787: inode #15: comm syz.1.3956: iget: bad i_size value: 360287970189639690
EXT4-fs (loop1): re-mounted 00000000-0000-0000-0000-000000000000 ro.