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

write to 0xffffffff86684ae8 of 8 bytes by task 4680 on cpu 1:
 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:2269
 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2329
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2363
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2373
 __netdev_printk+0x2d1/0x3e0 net/core/dev.c:11762
 netdev_info+0x99/0xc0 net/core/dev.c:11809
 __dev_set_allmulti+0x15b/0x240 net/core/dev.c:8698
 dev_set_allmulti+0x1f/0x30 net/core/dev.c:8724
 nbp_delete_promisc net/bridge/br_if.c:252 [inline]
 del_nbp+0x68/0x770 net/bridge/br_if.c:340
 br_dev_delete+0x4e/0xe0 net/bridge/br_if.c:386
 br_net_exit_batch_rtnl+0xca/0x170 net/bridge/br.c:369
 cleanup_net+0x3df/0x830 net/core/net_namespace.c:633
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x526/0x700 kernel/workqueue.c:3390
 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

read to 0xffffffff86684ae8 of 8 bytes by task 29 on cpu 0:
 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:2269
 vprintk_emit+0x10c/0x5e0 kernel/printk/printk.c:2329
 vprintk_deferred kernel/printk/printk.c:4057 [inline]
 _printk_deferred+0x83/0xb0 kernel/printk/printk.c:4066
 ___ratelimit+0x297/0x2b0 lib/ratelimit.c:56
 __printk_ratelimit+0x1c/0x30 kernel/printk/printk.c:4082
 kauditd_printk_skb kernel/audit.c:545 [inline]
 kauditd_hold_skb+0x61/0x1b0 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: 0x00000000000354c0 -> 0x00000000000d9fd8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 29 Comm: kauditd Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================
kauditd_printk_skb: 13 callbacks suppressed
audit: type=1400 audit(1722809864.205:2017): avc:  denied  { getattr } for  pid=14495 comm="syz.4.3333" name="/" dev="pidfs" ino=1 scontext=root:sysadm_r:sysadm_t tcontext=system_u:object_r:unlabeled_t tclass=filesystem permissive=1