audit: backlog limit exceeded
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=129818 audit_rate_limit=0 audit_backlog_limit=64
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff893aec88 of 23 bytes by task 30491 on cpu 1:
 vsnprintf+0x2ce/0x860 lib/vsprintf.c:2899
 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_log_start+0x709/0x730 kernel/audit.c:1949
 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
 file_map_prot_check+0x446/0x580 security/selinux/hooks.c:3959
 selinux_mmap_file+0x197/0x1e0 security/selinux/hooks.c:4012
 security_mmap_file+0x167/0x1b0 security/security.c:2505
 vm_mmap_pgoff+0x99/0x2d0 mm/util.c:575
 ksys_mmap_pgoff+0xc1/0x310 mm/mmap.c:605
 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10
 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 0xffffffff893aec88 of 8 bytes by task 3039 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_log_lost+0x1cc/0x200 kernel/audit.c:416
 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:4228
 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: 0x00000001000017fe -> 0x61203a7469647561

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3039 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=130307 audit_rate_limit=0 audit_backlog_limit=64
audit: backlog limit exceeded
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=130308 audit_rate_limit=0 audit_backlog_limit=64
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=130309 audit_rate_limit=0 audit_backlog_limit=64
audit: backlog limit exceeded