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BUG: KCSAN: data-race in _prb_read_valid / data_alloc

write to 0xffffffff86e8bfc8 of 8 bytes by task 29 on cpu 1:
 data_alloc+0x2fc/0x380 kernel/printk/printk_ringbuffer.c:1129
 prb_reserve+0x8e3/0xaf0 kernel/printk/printk_ringbuffer.c:1727
 vprintk_store+0x54e/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 kauditd_printk_skb kernel/audit.c:588 [inline]
 kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:623
 kauditd_send_queue+0x275/0x2d0 kernel/audit.c:808
 kauditd_thread+0x439/0x660 kernel/audit.c:932
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86e8bfc8 of 16 bytes by task 13790 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:496 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1934 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1982 [inline]
 _prb_read_valid+0x183/0x930 kernel/printk/printk_ringbuffer.c:2173
 desc_update_last_finalized+0x8f/0x170 kernel/printk/printk_ringbuffer.c:1573
 prb_final_commit+0x111/0x150 kernel/printk/printk_ringbuffer.c:1842
 vprintk_store+0x88f/0x910 kernel/printk/printk.c:2381
 vprintk_emit+0x1a4/0x610 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 __ext4_error_inode+0x298/0x3a0 fs/ext4/super.c:861
 ext4_do_update_inode fs/ext4/inode.c:5801 [inline]
 ext4_mark_iloc_dirty+0x347/0xe40 fs/ext4/inode.c:6473
 __ext4_mark_inode_dirty+0x31d/0x410 fs/ext4/inode.c:6707
 ext4_rename fs/ext4/namei.c:4022 [inline]
 ext4_rename2+0x22ed/0x23d0 fs/ext4/namei.c:4218
 vfs_rename+0x963/0xac0 fs/namei.c:6208
 filename_renameat2+0x3a4/0x6a0 fs/namei.c:6326
 __do_sys_rename fs/namei.c:6370 [inline]
 __se_sys_rename+0x4a/0x1c0 fs/namei.c:6366
 __x64_sys_rename+0x31/0x40 fs/namei.c:6366
 x64_sys_call+0x20fe/0x2550 arch/x86/include/generated/asm/syscalls_64.h:83
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 13790 Comm: syz.9.11139 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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