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BUG: KCSAN: data-race in _prb_read_valid / data_alloc

write to 0xffffffff86e93060 of 8 bytes by task 17557 on cpu 0:
 data_alloc+0x2fc/0x380 kernel/printk/printk_ringbuffer.c:1129
 prb_reserve+0x8e3/0xaf0 kernel/printk/printk_ringbuffer.c:1727
 vprintk_store+0x54e/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x610 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
 inode_doinit_use_xattr+0x29e/0x2d0 security/selinux/hooks.c:1405
 inode_doinit_with_dentry+0x59e/0x7b0 security/selinux/hooks.c:1510
 __inode_security_revalidate security/selinux/hooks.c:300 [inline]
 dentry_has_perm security/selinux/hooks.c:1712 [inline]
 selinux_inode_get_acl+0x108/0x210 security/selinux/hooks.c:3466
 security_inode_get_acl+0x84/0xc0 security/security.c:1998
 vfs_get_acl+0x98/0x170 fs/posix_acl.c:1186
 do_get_acl+0x39/0x2f0 fs/posix_acl.c:1295
 do_getxattr+0x170/0x2b0 fs/xattr.c:806
 filename_getxattr+0xb7/0x190 fs/xattr.c:837
 path_getxattrat fs/xattr.c:876 [inline]
 __do_sys_getxattr fs/xattr.c:908 [inline]
 __se_sys_getxattr fs/xattr.c:905 [inline]
 __x64_sys_getxattr+0x115/0x150 fs/xattr.c:905
 x64_sys_call+0x22ed/0x2550 arch/x86/include/generated/asm/syscalls_64.h:192
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86e93060 of 16 bytes by task 2971 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:496 [inline]
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1934 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1982 [inline]
 _prb_read_valid+0x183/0x930 kernel/printk/printk_ringbuffer.c:2173
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2245
 syslog_print+0x109/0x560 kernel/printk/printk.c:1612
 do_syslog+0x52b/0x7f0 kernel/printk/printk.c:1763
 __do_sys_syslog kernel/printk/printk.c:1855 [inline]
 __se_sys_syslog kernel/printk/printk.c:1853 [inline]
 __x64_sys_syslog+0x41/0x50 kernel/printk/printk.c:1853
 x64_sys_call+0x1d36/0x2550 arch/x86/include/generated/asm/syscalls_64.h:104
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2971 Comm: klogd Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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