==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve_in_last

write to 0xffffffff86874460 of 8 bytes by task 3965 on cpu 1:
 data_realloc kernel/printk/printk_ringbuffer.c:1193 [inline]
 prb_reserve_in_last+0xa96/0xba0 kernel/printk/printk_ringbuffer.c:1456
 vprintk_store+0x494/0x860 kernel/printk/printk.c:2273
 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
 show_free_areas mm/show_mem.c:383 [inline]
 __show_mem+0x10b8/0x1460 mm/show_mem.c:408
 warn_alloc_show_mem mm/page_alloc.c:3943 [inline]
 warn_alloc+0x189/0x1a0 mm/page_alloc.c:3968
 __vmalloc_node_range_noprof+0x9d/0xed0 mm/vmalloc.c:3834
 vmalloc_user_noprof+0x7d/0xb0 mm/vmalloc.c:4050
 xskq_create+0x80/0xe0 net/xdp/xsk_queue.c:49
 xsk_init_queue+0x95/0xf0 net/xdp/xsk.c:1114
 xsk_setsockopt+0x3f5/0x640 net/xdp/xsk.c:1528
 do_sock_setsockopt net/socket.c:2360 [inline]
 __sys_setsockopt+0x184/0x200 net/socket.c:2385
 __do_sys_setsockopt net/socket.c:2391 [inline]
 __se_sys_setsockopt net/socket.c:2388 [inline]
 __x64_sys_setsockopt+0x64/0x80 net/socket.c:2388
 x64_sys_call+0x20ec/0x3000 arch/x86/include/generated/asm/syscalls_64.h:55
 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

read to 0xffffffff86874458 of 16 bytes by task 2992 on cpu 0:
 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+0x23a/0x540 kernel/printk/printk.c:1623
 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: 0 UID: 0 PID: 2992 Comm: klogd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================