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

write to 0xffffffff8606ffd8 of 8 bytes by task 20101 on cpu 0:
 data_alloc+0x291/0x2c0 kernel/printk/printk_ringbuffer.c:1096
 prb_reserve+0x85e/0xb60 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2266
 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2326
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2360
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2370
 p9_fd_create+0x1ff/0x260 net/9p/trans_fd.c:1098
 p9_client_create+0x59a/0xa80 net/9p/client.c:1015
 v9fs_session_init+0xf9/0xda0 fs/9p/v9fs.c:410
 v9fs_mount+0x69/0x560 fs/9p/vfs_super.c:122
 legacy_get_tree+0x77/0xd0 fs/fs_context.c:662
 vfs_get_tree+0x56/0x1d0 fs/super.c:1780
 do_new_mount+0x227/0x690 fs/namespace.c:3352
 path_mount+0x49b/0xb30 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3875
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3875
 x64_sys_call+0x25c9/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff8606ffd8 of 8 bytes by task 29 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:482 [inline]
 desc_push_tail kernel/printk/printk_ringbuffer.c:778 [inline]
 desc_reserve kernel/printk/printk_ringbuffer.c:924 [inline]
 prb_reserve+0x235/0xb60 kernel/printk/printk_ringbuffer.c:1619
 vprintk_store+0x53f/0x810 kernel/printk/printk.c:2266
 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2326
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2360
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2370
 kauditd_printk_skb kernel/audit.c:546 [inline]
 kauditd_hold_skb+0x1a1/0x1b0 kernel/audit.c:581
 kauditd_send_queue+0x288/0x2e0 kernel/audit.c:766
 kauditd_thread+0x42a/0x650 kernel/audit.c:890
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0xfffffffffffeadf8 -> 0x00000000000a3248

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29 Comm: kauditd Not tainted 6.10.0-rc5-syzkaller-00012-g626737a5791b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================
audit: type=1400 audit(1719271993.372:20231): avc:  denied  { mounton } for  pid=20100 comm="syz.2.5414" path="/root/syzkaller.vMsNLl/559/file1/file0" dev="loop2" ino=1065 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:dosfs_t tclass=dir permissive=1