audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=20816 audit_rate_limit=0 audit_backlog_limit=64
audit: backlog limit exceeded
==================================================================
BUG: KCSAN: data-race in data_push_tail / string

write to 0xffffffff893c19f8 of 1 bytes by task 24155 on cpu 1:
 string_nocheck lib/vsprintf.c:659 [inline]
 string+0x187/0x220 lib/vsprintf.c:737
 vsnprintf+0x532/0x860 lib/vsprintf.c:2948
 vscnprintf+0x41/0x90 lib/vsprintf.c:3013
 printk_sprint+0x30/0x2e0 kernel/printk/printk.c:2222
 vprintk_store+0x57b/0x910 kernel/printk/printk.c:2364
 vprintk_emit+0x1a4/0x600 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
 audit_panic kernel/audit.c:348 [inline]
 audit_log_lost+0x1e5/0x200 kernel/audit.c:420
 audit_log_start+0x46f/0x730 kernel/audit.c:-1
 common_lsm_audit+0x65/0x230 security/lsm_audit.c:442
 slow_avc_audit+0x14c/0x190 security/selinux/avc.c:779
 avc_audit security/selinux/include/avc.h:131 [inline]
 avc_has_perm+0x144/0x190 security/selinux/avc.c:1198
 selinux_perf_event_open+0xd3/0xe0 security/selinux/hooks.c:7290
 security_perf_event_open+0x30/0x60 security/security.c:5466
 __do_sys_perf_event_open kernel/events/core.c:13832 [inline]
 __se_sys_perf_event_open+0xc0/0x1290 kernel/events/core.c:13805
 __x64_sys_perf_event_open+0x67/0x80 kernel/events/core.c:13805
 x64_sys_call+0x2789/0x3020 arch/x86/include/generated/asm/syscalls_64.h:299
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff893c19f8 of 8 bytes by task 3040 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline]
 data_push_tail+0x100/0x470 kernel/printk/printk_ringbuffer.c:693
 data_alloc+0x11b/0x390 kernel/printk/printk_ringbuffer.c:1089
 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 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
 audit_panic kernel/audit.c:348 [inline]
 audit_log_lost+0x1e5/0x200 kernel/audit.c:420
 audit_log_start+0x46f/0x730 kernel/audit.c:-1
 common_lsm_audit+0x65/0x230 security/lsm_audit.c:442
 slow_avc_audit+0x14c/0x190 security/selinux/avc.c:779
 avc_audit security/selinux/include/avc.h:131 [inline]
 avc_has_perm+0x144/0x190 security/selinux/avc.c:1198
 sock_has_perm security/selinux/hooks.c:4820 [inline]
 selinux_socket_recvmsg+0x192/0x1c0 security/selinux/hooks.c:5167
 security_socket_recvmsg+0x4c/0x90 security/security.c:4227
 sock_recvmsg+0x38/0x120 net/socket.c:1098
 ____sys_recvmsg+0xf5/0x280 net/socket.c:2812
 ___sys_recvmsg+0x11f/0x3b0 net/socket.c:2854
 __sys_recvmsg net/socket.c:2887 [inline]
 __do_sys_recvmsg net/socket.c:2893 [inline]
 __se_sys_recvmsg net/socket.c:2890 [inline]
 __x64_sys_recvmsg+0xd1/0x160 net/socket.c:2890
 x64_sys_call+0x2b1a/0x3020 arch/x86/include/generated/asm/syscalls_64.h:48
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000ffffeb51 -> 0x6378652074696d69

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3040 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=20834 audit_rate_limit=0 audit_backlog_limit=64
audit: backlog limit exceeded
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=20886 audit_rate_limit=0 audit_backlog_limit=64