Hello, I am seeing what looks like a kernel bug in the Geneve/OVS/vhost transmit path on a Talos Linux node running Kube-ovn with Geneve overlay and KubeVirt VM traffic.
Environment: Kernel: 6.18.33-talos Distro: Talos v1.13.3 Compiler/config: CONFIG_CC_VERSION_TEXT="clang version 22.1.2" CONFIG_CC_IS_CLANG=y CONFIG_LTO=y CONFIG_LTO_CLANG=y CONFIG_LTO_CLANG_THIN=y CONFIG_FORTIFY_SOURCE=y Hardware: HPE ProLiant DL325 Gen11, AMD EPYC NIC driver: bnxt_en Workload/network: Kube-OVN, Geneve overlay Open vSwitch datapath KubeVirt/QEMU VM traffic via vhost/tap Relevant console output: [ 648.742603] memcpy: detected buffer overflow: 104 byte write of buffer size 96 [ 648.749907] WARNING: CPU: 61 PID: 27020 at lib/string_helpers.c:1036 __fortify_report+0x45/0x60 [ 648.758689] Modules linked in: dm_round_robin dm_multipath lpfc nvmet_fc nvmet intel_rapl_msr intel_rapl_common ahci nvme_auth bnxt_en nvme hpilo hkdf libahci sp5100_tco watchdog k10temp [ 648.775429] CPU: 61 UID: 107 PID: 27020 Comm: vhost-27002 Not tainted 6.18.29-talos #1 PREEMPT(none) [ 648.784735] Hardware name: HPE ProLiant DL325 Gen11/ProLiant DL325 Gen11, BIOS 2.84 11/05/2025 [ 648.890478] skb_tunnel_info_unclone+0x179/0x190 [ 648.895152] geneve_xmit+0x7fe/0xe00 [ 648.907240] dev_hard_start_xmit+0xa7/0x1f0 [ 648.911479] __dev_queue_xmit+0x864/0xf40 [ 648.919688] do_execute_actions+0x9b9/0x1be0 [ 648.927727] ovs_execute_actions+0x58/0x170 [ 648.931960] ovs_dp_process_packet+0xb1/0x1c0 [ 648.936370] ovs_vport_receive+0x90/0x100 [ 648.940428] netdev_frame_hook+0x146/0x1a0 [ 648.954093] __netif_receive_skb+0x3f/0x160 [ 648.958324] process_backlog+0x10c/0x210 [ 648.962295] __napi_poll+0x2f/0x190 [ 648.965832] net_rx_action+0x2e3/0x500 [ 648.969632] handle_softirqs+0xe7/0x310 [ 648.985387] tun_get_user+0x137e/0x1510 [ 649.005878] handle_tx+0x41f/0xd30 [ 649.029014] vhost_run_work_list+0x52/0x90 [ 649.033162] vhost_task_fn+0xc2/0x140 [ 649.064145] ---[ end trace 0000000000000000 ]--- [ 649.068820] ------------[ cut here ]------------ [ 649.073489] kernel BUG at lib/string_helpers.c:1043! I don't know whether this is a real overflow or a FORTIFY false-positive. I cannot reproduce the issue on Talos v1.12.X which uses a gcc built kernel, whereas the affected kernel is built with clang. Don't know whether this is relevant here. I am currently trying to make a reliable reproducer, but I can almost always trigger the issue when iperf stressing the VM-network. Please let me know if this should go to a more specific maintainer/list or further info is needed. I am able to test candidate patches if provided. Downstream bug reports: https://github.com/siderolabs/talos/issues/13440 https://github.com/kubeovn/kube-ovn/issues/6767 Thanks, Johan _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
