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

write to 0xffffffff8686f4d0 of 8 bytes by task 3739 on cpu 0:
 data_alloc+0x27d/0x2b0 kernel/printk/printk_ringbuffer.c:1096
 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
 __netdev_printk+0x321/0x3e0 net/core/dev.c:12517
 netdev_info+0x9b/0xd0 net/core/dev.c:12564
 bond_uninit+0x1ee/0x330 drivers/net/bonding/bond_main.c:6076
 unregister_netdevice_many_notify+0x119c/0x1690 net/core/dev.c:12098
 unregister_netdevice_many+0x19/0x20 net/core/dev.c:12140
 ops_exit_rtnl_list net/core/net_namespace.c:188 [inline]
 ops_undo_list+0x213/0x410 net/core/net_namespace.c:249
 cleanup_net+0x2de/0x4d0 net/core/net_namespace.c:686
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff8686f4d0 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+0x221/0xaf0 kernel/printk/printk_ringbuffer.c:1619
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x178/0x650 kernel/printk/printk.c:2426
 vprintk_deferred kernel/printk/printk.c:4602 [inline]
 _printk_deferred+0x82/0xb0 kernel/printk/printk.c:4611
 ___ratelimit+0x4b1/0x4f0 lib/ratelimit.c:86
 __printk_ratelimit+0x1c/0x30 kernel/printk/printk.c:4627
 kauditd_printk_skb kernel/audit.c:545 [inline]
 kauditd_hold_skb+0x63/0x1c0 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+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0xfffffffffffd19b8 -> 0x0000000000085378

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29 Comm: kauditd Not tainted 6.16.0-rc4-syzkaller-00013-g66701750d556 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
kauditd_printk_skb: 524 callbacks suppressed
audit: type=1326 audit(1751339006.345:34889): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=root:sysadm_r:sysadm_t pid=15576 comm="syz.4.4244" exe="/root/syz-executor" sig=9 arch=c000003e syscall=231 compat=0 ip=0x7f1bfbbae929 code=0x0