BUG: KCSAN: data-race in _prb_read_valid / data_alloc write to 0xffffffff86c6bbb0 of 8 bytes by task 28 on cpu 1: data_alloc+0x310/0x390 kernel/printk/printk_ringbuffer.c:1129 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 kauditd_printk_skb kernel/audit.c:587 [inline] kauditd_hold_skb+0x1b1/0x1c0 kernel/audit.c:622 kauditd_send_queue+0x273/0x2c0 kernel/audit.c:807 kauditd_thread+0x444/0x670 kernel/audit.c:931 kthread+0x22a/0x280 kernel/kthread.c:467 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff86c6bbb0 of 16 bytes by task 14322 on cpu 0: desc_read kernel/printk/printk_ringbuffer.c:496 [inline] desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1931 [inline] prb_read kernel/printk/printk_ringbuffer.c:1979 [inline] _prb_read_valid+0x1bc/0x950 kernel/printk/printk_ringbuffer.c:2170 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2242 __console_flush_and_unlock kernel/printk/printk.c:3392 [inline] console_unlock+0x146/0x280 kernel/printk/printk.c:3413 vprintk_emit+0x3e4/0x600 kernel/printk/printk.c:2479 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2504 caif_netlink_parms net/caif/chnl_net.c:424 [inline] ipcaif_newlink+0x147/0x2a0 net/caif/chnl_net.c:450 rtnl_newlink_create+0x1e4/0x650 net/core/rtnetlink.c:3840 __rtnl_newlink net/core/rtnetlink.c:3957 [inline] rtnl_newlink+0x10a0/0x1330 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6985 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x470/0x4d0 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0x76/0x90 net/socket.c:2209 x64_sys_call+0x2d35/0x3020 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 14322 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 ================================================================== bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state bridge_slave_0: entered allmulticast mode bridge_slave_0: entered promiscuous mode bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_1: entered allmulticast mode bridge_slave_1: entered promiscuous mode bond0: (slave bond_slave_0): Enslaving as an active interface with an up link bond0: (slave bond_slave_1): Enslaving as an active interface with an up link team0: Port device team_slave_0 added team0: Port device team_slave_1 added batman_adv: batadv0: Adding interface: batadv_slave_0 batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active batman_adv: batadv0: Adding interface: batadv_slave_1 batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active hsr_slave_0: entered promiscuous mode hsr_slave_1: entered promiscuous mode netdevsim netdevsim5 netdevsim0: renamed from eth0 netdevsim netdevsim5 netdevsim1: renamed from eth1 netdevsim netdevsim5 netdevsim2: renamed from eth2 netdevsim netdevsim5 netdevsim3: renamed from eth3 8021q: adding VLAN 0 to HW filter on device bond0 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device batadv0 veth0_vlan: entered promiscuous mode veth1_vlan: entered promiscuous mode veth0_macvtap: entered promiscuous mode veth1_macvtap: entered promiscuous mode batman_adv: batadv0: Interface activated: batadv_slave_0 batman_adv: batadv0: Interface activated: batadv_slave_1