audit: type=1326 audit(1754199936.226:26731): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=29690 comm="syz.1.6899" exe="/root/syz-executor" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7f2949a2eb69 code=0x7ffc0000
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff88e220d0 of 43 bytes by task 29691 on cpu 1:
 vsnprintf+0x2ce/0x890 lib/vsprintf.c:2826
 vscnprintf+0x41/0x90 lib/vsprintf.c:2939
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2216
 vprintk_store+0x599/0x860 kernel/printk/printk.c:2336
 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
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x24d/0x280 lib/fault-inject.c:174
 should_failslab+0x8c/0xb0 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4133 [inline]
 slab_alloc_node mm/slub.c:4209 [inline]
 kmem_cache_alloc_node_noprof+0x57/0x320 mm/slub.c:4281
 __alloc_skb+0x101/0x320 net/core/skbuff.c:659
 alloc_skb include/linux/skbuff.h:1336 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 audit_buffer_alloc kernel/audit.c:1795 [inline]
 audit_log_start+0x380/0x6c0 kernel/audit.c:1913
 audit_seccomp+0x48/0x100 kernel/auditsc.c:3001
 seccomp_log kernel/seccomp.c:1033 [inline]
 __seccomp_filter+0x69d/0x10d0 kernel/seccomp.c:1328
 __secure_computing+0x82/0x150 kernel/seccomp.c:1388
 syscall_trace_enter+0xcf/0x1e0 kernel/entry/syscall-common.c:44
 syscall_enter_from_user_mode_work include/linux/entry-common.h:95 [inline]
 syscall_enter_from_user_mode include/linux/entry-common.h:125 [inline]
 do_syscall_64+0xac/0x200 arch/x86/entry/syscall_64.c:90
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff88e220e0 of 8 bytes by task 29 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:594 [inline]
 data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:679
 data_alloc+0xbf/0x2b0 kernel/printk/printk_ringbuffer.c:1054
 prb_reserve+0x808/0xaf0 kernel/printk/printk_ringbuffer.c:1669
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 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
 kauditd_printk_skb kernel/audit.c:546 [inline]
 kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:581
 kauditd_send_queue+0x273/0x2c0 kernel/audit.c:766
 kauditd_thread+0x421/0x630 kernel/audit.c:890
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xdd/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000100001165 -> 0x676e6963726f6620

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 29 Comm: kauditd Tainted: G        W           6.16.0-syzkaller-11241-g186f3edfdd41 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================
audit: type=1326 audit(1754199936.226:26732): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=29690 comm="syz.1.6899" exe="/root/syz-executor" sig=0 arch=c000003e syscall=257 compat=0 ip=0x7f2949a2d4d0 code=0x7ffc0000
audit: type=1326 audit(1754199936.226:26733): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=29690 comm="syz.1.6899" exe="/root/syz-executor" sig=0 arch=c000003e syscall=1 compat=0 ip=0x7f2949a2d61f code=0x7ffc0000