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BUG: KCSAN: data-race in _prb_read_valid / prb_reserve_in_last

write to 0xffffffff86874848 of 8 bytes by task 5268 on cpu 0:
 data_realloc kernel/printk/printk_ringbuffer.c:1177 [inline]
 prb_reserve_in_last+0x861/0xb80 kernel/printk/printk_ringbuffer.c:1440
 vprintk_store+0x494/0x860 kernel/printk/printk.c:2300
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 show_free_areas mm/show_mem.c:376 [inline]
 __show_mem+0x10e1/0x1490 mm/show_mem.c:401
 warn_alloc_show_mem mm/page_alloc.c:3908 [inline]
 warn_alloc+0x189/0x1a0 mm/page_alloc.c:3933
 __vmalloc_node_range_noprof+0x9c/0xe00 mm/vmalloc.c:3830
 vmalloc_user_noprof+0x7d/0xb0 mm/vmalloc.c:4046
 xskq_create+0x80/0xe0 net/xdp/xsk_queue.c:49
 xsk_init_queue+0x95/0xf0 net/xdp/xsk.c:1026
 xsk_setsockopt+0x477/0x640 net/xdp/xsk.c:1371
 do_sock_setsockopt net/socket.c:2344 [inline]
 __sys_setsockopt+0x184/0x200 net/socket.c:2369
 __do_sys_setsockopt net/socket.c:2375 [inline]
 __se_sys_setsockopt net/socket.c:2372 [inline]
 __x64_sys_setsockopt+0x64/0x80 net/socket.c:2372
 x64_sys_call+0x20ec/0x2ff0 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 0xffffffff86874840 of 16 bytes by task 2980 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1874 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x1bc/0x920 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185
 syslog_print+0x23a/0x540 kernel/printk/printk.c:1650
 do_syslog+0x52b/0x7e0 kernel/printk/printk.c:1785
 __do_sys_syslog kernel/printk/printk.c:1877 [inline]
 __se_sys_syslog kernel/printk/printk.c:1875 [inline]
 __x64_sys_syslog+0x41/0x50 kernel/printk/printk.c:1875
 x64_sys_call+0x2f36/0x2ff0 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 6.17.0-rc1-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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