syzbot

team_slave_1: entered allmulticast mode
bridge0: port 3(team0) entered blocking state
bridge0: port 3(team0) entered forwarding state
==================================================================
BUG: KCSAN: data-race in data_push_tail / number

write to 0xffffffff88e172b8 of 1 bytes by task 7067 on cpu 0:
 number+0x81f/0xab0 lib/vsprintf.c:558
 vsnprintf+0x691/0x890 lib/vsprintf.c:2816
 vscnprintf+0x41/0x90 lib/vsprintf.c:2917
 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
 debug_print_tree+0xcc/0x110 fs/ext4/block_validity.c:138
 ext4_setup_system_zone+0x45b/0x610 fs/ext4/block_validity.c:265
 __ext4_fill_super fs/ext4/super.c:5533 [inline]
 ext4_fill_super+0x2e0b/0x34e0 fs/ext4/super.c:5726
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5758
 vfs_get_tree+0x57/0x1d0 fs/super.c:1759
 do_new_mount+0x207/0x680 fs/namespace.c:3881
 path_mount+0x4a4/0xb20 fs/namespace.c:4208
 do_mount fs/namespace.c:4221 [inline]
 __do_sys_mount fs/namespace.c:4432 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4409
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4409
 x64_sys_call+0xd36/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff88e172b8 of 8 bytes by task 7057 on cpu 1:
 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
 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_add_if+0x8f6/0xa60 net/bridge/br_if.c:687
 br_add_slave+0x2c/0x40 net/bridge/br_device.c:375
 do_set_master+0x390/0x460 net/core/rtnetlink.c:2946
 do_setlink+0x97f/0x27f0 net/core/rtnetlink.c:3159
 rtnl_changelink net/core/rtnetlink.c:3769 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3928 [inline]
 rtnl_newlink+0xe75/0x12d0 net/core/rtnetlink.c:4065
 rtnetlink_rcv_msg+0x5fb/0x6d0 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x120/0x220 net/netlink/af_netlink.c:2534
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6982
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x59e/0x670 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x142/0x180 net/socket.c:727
 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2566
 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2655
 x64_sys_call+0x2999/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000ffffe1f2 -> 0x00000000ffff0038

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 7057 Comm: syz.3.1044 Not tainted 6.15.0-rc7-syzkaller-00152-gd0c22de9995b #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
syz.3.1044 (7057) used greatest stack depth: 8792 bytes left