================================================================== BUG: KCSAN: data-race in _prb_read_valid / data_alloc write to 0xffffffff86880d78 of 8 bytes by task 29 on cpu 0: data_alloc+0x274/0x2e0 kernel/printk/printk_ringbuffer.c:1101 prb_reserve+0x807/0xaf0 kernel/printk/printk_ringbuffer.c:1685 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2299 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2448 kauditd_printk_skb kernel/audit.c:583 [inline] kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:618 kauditd_send_queue+0x270/0x2c0 kernel/audit.c:803 kauditd_thread+0x421/0x630 kernel/audit.c:927 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff86880d78 of 16 bytes by task 2980 on cpu 1: desc_read kernel/printk/printk_ringbuffer.c:479 [inline] desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1892 [inline] prb_read kernel/printk/printk_ringbuffer.c:1940 [inline] _prb_read_valid+0x1bc/0x920 kernel/printk/printk_ringbuffer.c:2131 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2203 syslog_print+0xeb/0x540 kernel/printk/printk.c:1606 do_syslog+0x52b/0x7e0 kernel/printk/printk.c:1758 __do_sys_syslog kernel/printk/printk.c:1850 [inline] __se_sys_syslog kernel/printk/printk.c:1848 [inline] __x64_sys_syslog+0x41/0x50 kernel/printk/printk.c:1848 x64_sys_call+0x2f45/0x3000 arch/x86/include/generated/asm/syscalls_64.h:104 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 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 2980 Comm: klogd Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 ==================================================================