================================================================== BUG: KCSAN: data-race in data_alloc / prb_reserve write to 0xffffffff8666ccc0 of 8 bytes by task 7168 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+0x558/0x870 kernel/printk/printk.c:2326 vprintk_emit+0x168/0x690 kernel/printk/printk.c:2408 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82 _printk+0x7a/0xa0 kernel/printk/printk.c:2457 __ext4_msg+0x18e/0x1a0 fs/ext4/super.c:998 ext4_put_super+0x91/0x810 fs/ext4/super.c:1303 generic_shutdown_super+0xe5/0x220 fs/super.c:642 kill_block_super+0x2a/0x70 fs/super.c:1710 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7368 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473 deactivate_super+0x9f/0xb0 fs/super.c:506 cleanup_mnt+0x268/0x2e0 fs/namespace.c:1413 __cleanup_mnt+0x19/0x20 fs/namespace.c:1420 task_work_run+0x13a/0x1a0 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff8666ccc0 of 8 bytes by task 12276 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+0x558/0x870 kernel/printk/printk.c:2326 vprintk_emit+0x168/0x690 kernel/printk/printk.c:2408 dev_vprintk_emit+0x23c/0x2a0 drivers/base/core.c:4891 dev_printk_emit+0x82/0xb0 drivers/base/core.c:4902 __netdev_printk+0x352/0x3e0 net/core/dev.c:12299 netdev_info+0x99/0xc0 net/core/dev.c:12354 nsim_udp_tunnel_set_port+0x175/0x190 drivers/net/netdevsim/udp_tunnels.c:34 udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:246 [inline] __udp_tunnel_nic_device_sync+0x57b/0x9e0 net/ipv4/udp_tunnel_nic.c:289 udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:312 [inline] __udp_tunnel_nic_add_port+0x66d/0x6e0 net/ipv4/udp_tunnel_nic.c:531 udp_tunnel_nic_add_port include/net/udp_tunnel.h:350 [inline] udp_tunnel_push_rx_port+0xea/0x120 net/ipv4/udp_tunnel_core.c:96 geneve_offload_rx_ports drivers/net/geneve.c:1176 [inline] geneve_netdevice_event+0x169/0x1c0 drivers/net/geneve.c:1881 notifier_call_chain kernel/notifier.c:85 [inline] raw_notifier_call_chain+0x6f/0x1d0 kernel/notifier.c:453 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:2206 call_netdevice_notifiers_extack net/core/dev.c:2244 [inline] call_netdevice_notifiers+0x49/0x70 net/core/dev.c:2258 udp_tunnel_get_rx_info include/net/udp_tunnel.h:138 [inline] udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:825 [inline] udp_tunnel_nic_netdevice_event+0xa49/0xc80 net/ipv4/udp_tunnel_nic.c:893 notifier_call_chain kernel/notifier.c:85 [inline] raw_notifier_call_chain+0x6f/0x1d0 kernel/notifier.c:453 call_netdevice_notifiers_info+0xae/0x100 net/core/dev.c:2206 call_netdevice_notifiers_extack net/core/dev.c:2244 [inline] call_netdevice_notifiers net/core/dev.c:2258 [inline] register_netdevice+0xcf4/0xeb0 net/core/dev.c:10981 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:929 [inline] nsim_create+0x564/0x6b0 drivers/net/netdevsim/netdev.c:989 __nsim_dev_port_add+0x48e/0x650 drivers/net/netdevsim/dev.c:1393 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1449 [inline] nsim_dev_reload_create drivers/net/netdevsim/dev.c:1501 [inline] nsim_dev_reload_up+0x433/0x510 drivers/net/netdevsim/dev.c:988 devlink_reload+0x31a/0x5a0 net/devlink/dev.c:474 devlink_nl_reload_doit+0x4dd/0x8f0 net/devlink/dev.c:584 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x620/0x6d0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2533 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x599/0x670 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x5cc/0x6e0 net/netlink/af_netlink.c:1882 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:733 ____sys_sendmsg+0x326/0x4b0 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x19d/0x230 net/socket.c:2659 __do_sys_sendmsg net/socket.c:2664 [inline] __se_sys_sendmsg net/socket.c:2662 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2662 x64_sys_call+0x2734/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0xfffffffffffd5070 -> 0x00000000000875b0 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 12276 Comm: syz.3.2997 Tainted: G W 6.14.0-rc7-syzkaller-00074-ga7f2e10ecd8f #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 ================================================================== netdevsim netdevsim3 eth0: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 eth1: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 eth2: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 eth3: set [1, 0] type 2 family 0 port 6081 - 0