==================================================================
BUG: KCSAN: data-race in data_alloc / prb_reserve

write to 0xffffffff85c61098 of 8 bytes by task 27 on cpu 1:
 data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1088
 prb_reserve+0x897/0xbc0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 kauditd_printk_skb kernel/audit.c:546 [inline]
 kauditd_hold_skb+0x19d/0x1b0 kernel/audit.c:581
 kauditd_send_queue+0x27a/0x2d0 kernel/audit.c:766
 kauditd_thread+0x42a/0x640 kernel/audit.c:890
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243

read to 0xffffffff85c61098 of 8 bytes by task 19736 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:478 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:774 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:920 [inline]
 prb_reserve+0x229/0xbc0 kernel/printk/printk_ringbuffer.c:1505
 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_deferred kernel/printk/printk.c:3945 [inline]
 _printk_deferred+0x83/0xb0 kernel/printk/printk.c:3954
 ___ratelimit+0x293/0x2b0 lib/ratelimit.c:56
 __nla_validate_parse+0x1616/0x1ce0 lib/nlattr.c:647
 __nla_parse+0x40/0x50 lib/nlattr.c:732
 __nlmsg_parse include/net/netlink.h:756 [inline]
 nlmsg_parse_deprecated include/net/netlink.h:797 [inline]
 xfrm_user_rcv_msg+0x386/0x4f0 net/xfrm/xfrm_user.c:3153
 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2543
 xfrm_netlink_rcv+0x47/0x60 net/xfrm/xfrm_user.c:3186
 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
 netlink_unicast+0x589/0x660 net/netlink/af_netlink.c:1367
 netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmsg+0x1e9/0x270 net/socket.c:2667
 __do_sys_sendmsg net/socket.c:2676 [inline]
 __se_sys_sendmsg net/socket.c:2674 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xfffffffffffc3888 -> 0x0000000000061150

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19736 Comm: syz-executor.0 Not tainted 6.8.0-rc7-syzkaller-00260-gfa4b851b4ad6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================
__nla_validate_parse: 8 callbacks suppressed
netlink: 112 bytes leftover after parsing attributes in process `syz-executor.0'.