netdevsim netdevsim4 eth2 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim4 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 ================================================================== BUG: KCSAN: data-race in data_push_tail / vsnprintf write to 0xffffffff88e6cf50 of 3 bytes by task 7114 on cpu 0: vsnprintf+0x2ce/0x890 lib/vsprintf.c:2878 vscnprintf+0x41/0x90 lib/vsprintf.c:2991 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2189 vprintk_store+0x599/0x860 kernel/printk/printk.c:2309 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x79/0xa0 kernel/printk/printk.c:2448 __ext4_msg+0x18f/0x1a0 fs/ext4/super.c:990 ext4_fill_super+0x2fcb/0x3810 fs/ext4/super.c:5751 get_tree_bdev_flags+0x291/0x300 fs/super.c:1698 get_tree_bdev+0x1f/0x30 fs/super.c:1721 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5768 vfs_get_tree+0x57/0x1d0 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount+0x24d/0x660 fs/namespace.c:3718 path_mount+0x4a5/0xb70 fs/namespace.c:4028 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4206 __x64_sys_mount+0x67/0x80 fs/namespace.c:4206 x64_sys_call+0x2b51/0x3000 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff88e6cf50 of 8 bytes by task 7118 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:591 [inline] data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:676 data_alloc+0xfb/0x2e0 kernel/printk/printk_ringbuffer.c:1061 prb_reserve+0x807/0xaf0 kernel/printk/printk_ringbuffer.c:1685 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2299 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399 dev_vprintk_emit+0x242/0x2a0 drivers/base/core.c:4914 dev_printk_emit+0x84/0xb0 drivers/base/core.c:4925 __netdev_printk+0x35c/0x3e0 net/core/dev.c:12716 netdev_info+0x9b/0xd0 net/core/dev.c:12771 nsim_udp_tunnel_unset_port+0x18a/0x1b0 drivers/net/netdevsim/udp_tunnels.c:59 udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline] udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:249 [inline] __udp_tunnel_nic_device_sync+0x567/0x9c0 net/ipv4/udp_tunnel_nic.c:292 udp_tunnel_nic_flush+0x21b/0x300 net/ipv4/udp_tunnel_nic.c:694 udp_tunnel_nic_unregister net/ipv4/udp_tunnel_nic.c:901 [inline] udp_tunnel_nic_netdevice_event+0x8ea/0xdd0 net/ipv4/udp_tunnel_nic.c:942 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 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] unregister_netdevice_many_notify+0xe76/0x1690 net/core/dev.c:12284 unregister_netdevice_many net/core/dev.c:12347 [inline] unregister_netdevice_queue+0x1f5/0x220 net/core/dev.c:12161 unregister_netdevice include/linux/netdevice.h:3389 [inline] nsim_destroy+0xfa/0x2f0 drivers/net/netdevsim/netdev.c:1178 __nsim_dev_port_del+0xcf/0x110 drivers/net/netdevsim/dev.c:1473 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1485 [inline] nsim_dev_reload_destroy+0x1a3/0x2c0 drivers/net/netdevsim/dev.c:1707 nsim_dev_reload_down+0x67/0x80 drivers/net/netdevsim/dev.c:983 devlink_reload+0xad/0x580 net/devlink/dev.c:461 devlink_nl_reload_doit+0x503/0x8f0 net/devlink/dev.c:584 genl_family_rcv_msg_doit+0x143/0x1b0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x422/0x460 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x145/0x180 net/socket.c:742 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2630 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2719 x64_sys_call+0x191e/0x3000 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000ffffe6f4 -> 0x00000000ff203a29 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 7118 Comm: syz.4.1336 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 ================================================================== netdevsim netdevsim4 eth1 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim4 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim4 eth0 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim4 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0