bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff86946d48 of 88 bytes by task 29 on cpu 1:
 prb_reserve+0x696/0xaf0 kernel/printk/printk_ringbuffer.c:1635
 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:463
 ret_from_fork+0x11f/0x1b0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86946d48 of 8 bytes by task 18044 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x383/0x920 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2185
 __console_flush_and_unlock kernel/printk/printk.c:3304 [inline]
 console_unlock+0x164/0x330 kernel/printk/printk.c:3325
 vprintk_emit+0x388/0x650 kernel/printk/printk.c:2450
 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
 br_set_state+0x28c/0x390 net/bridge/br_stp.c:57
 br_make_forwarding+0xbc/0x150 net/bridge/br_stp.c:455
 br_port_state_selection+0x113/0x330 net/bridge/br_stp.c:-1
 br_stp_enable_port+0xd4/0x110 net/bridge/br_stp_if.c:94
 br_port_carrier_check+0x200/0x230 net/bridge/br_if.c:89
 br_device_event+0x3ce/0x5f0 net/bridge/br.c:96
 notifier_call_chain kernel/notifier.c:85 [inline]
 raw_notifier_call_chain+0x6f/0x1b0 kernel/notifier.c:453
 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:2229
 netif_state_change+0x16d/0x1f0 net/core/dev.c:1583
 linkwatch_do_dev+0xb9/0xf0 net/core/link_watch.c:186
 __linkwatch_run_queue+0x582/0x850 net/core/link_watch.c:244
 linkwatch_event+0x40/0x50 net/core/link_watch.c:304
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x11f/0x1b0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000000003fd1 -> 0x0000000000005fd1

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 18044 Comm: kworker/u8:25 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound linkwatch_event
==================================================================
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
netdevsim netdevsim6 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim6 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0