More test results: * This issue can be reproduced with 5.4.0-59.65~18.04.1 and 5.4.0-58.64~18.04.1, and even with 5.4.0-52.57~18.04.1 on node entei. * This issue cannot be reproduced when you run these two tests directly with "sudo ./reuseport_bpf_cpu" and "sudo ./reuseport_bpf_numa" * This issue cannot be reproduced when you run the whole net test suite with "sudo make run_tests TARGETS=net in tools/testing/selftests/ of the source tree. * This issue can be reproduced when you run the whole ubuntu_kernel_selftest suite with "AUTOTEST_PATH=/home/ubuntu/autotest sudo -E autotest/client/autotest-local --verbose autotest/client/tests/ubuntu_kernel_selftests/control", so it looks like some test before the net test ('setup','breakpoints','cpu-hotplug','efivarfs','memfd','memory-hotplug','mount') will make the net test crash with this. And I managed to get the kernel panic log when this happens: entei login: [ 3062.665272] BUG: Unable to handle kernel instruction fetch [ 3062.665461] Faulting instruction address: 0x7fe000087fe00008 [ 3062.665507] Oops: Kernel access of bad area, sig: 11 [#1] [ 3062.665566] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV [ 3062.665705] Modules linked in: sch_fq dccp_ipv6 dccp_ipv4 dccp ip6table_filter xt_conntrack nf_conntrack nf_defrag_ipv4 ip6_tables nf_defrag_ipv6 ip_vti ip6_vti fou6 sit ipip tunnel4 geneve act_mirred cls_basic esp6 authenc echainiv xt_policy iptable_filter bpfilter veth esp4_offload esp4 xfrm_user xfrm_algo macsec fou vxlan ip6_udp_tunnel udp_tunnel vrf 8021q garp mrp bridge stp llc ip6_gre ip6_tunnel tunnel6 ip_gre ip_tunnel gre cls_u32 sch_htb dummy tls binfmt_misc input_leds joydev mac_hid ofpart cmdlinepart powernv_flash at24 ipmi_powernv ipmi_devintf mtd ipmi_msghandler uio_pdrv_genirq uio opal_prd powernv_rng vmx_crypto sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid ast drm_vram_helper i2c_algo_bit ttm drm_kms_helper crct10dif_vpmsum [ 3062.665793] crc32c_vpmsum syscopyarea sysfillrect sysimgblt fb_sys_fops drm hid ahci libahci drm_panel_orientation_quirks tg3 [last unloaded: notifier_error_inject] [ 3062.666150] CPU: 0 PID: 53591 Comm: reuseport_bpf_c Tainted: G W 5.4.0-58-generic #64~18.04.1-Ubuntu [ 3062.666181] NIP: 7fe000087fe00008 LR: c000000000d20004 CTR: 7fe000087fe00008 [ 3062.666208] REGS: c0000007ff6f7580 TRAP: 0480 Tainted: G W (5.4.0-58-generic) [ 3062.666235] MSR: 9000000000009033 CR: 24002228 XER: 20000000 [ 3062.666265] CFAR: c000000000d20000 IRQMASK: 0 [ 3062.666265] GPR00: c000000000da196c c0000007ff6f7810 c000000001abf800 c000000662e546e0 [ 3062.666265] GPR04: c008000003cd0038 c000000662e546e0 0000000000000028 000000006a17a667 [ 3062.666265] GPR08: fffffffe031e7987 7fe000087fe00008 c0000007666a5158 0000000000000000 [ 3062.666265] GPR12: 7fe000087fe00008 c0000007ff7fee00 0000000000000000 00000000000022b8 [ 3062.666265] GPR16: 000000000100007f 0000000000007fdb 000000000100007f c0000000019ef800 [ 3062.666265] GPR20: 0000000000007fdb 0000000000000000 0000000000000000 00000000000022b8 [ 3062.666265] GPR24: 0000000000000000 0000000000000080 c0000000019ef800 0000000000000028 [ 3062.666265] GPR28: c008000003cd0000 c000000662e546e0 00000000750c5235 c000000005987800 [ 3062.666564] NIP [7fe000087fe00008] 0x7fe000087fe00008 [ 3062.666590] LR [c000000000d20004] reuseport_select_sock+0x104/0x420 [ 3062.666612] Call Trace: [ 3062.666629] [c0000007ff6f7810] [c0000007ff6f78c0] 0xc0000007ff6f78c0 (unreliable) [ 3062.666658] [c0000007ff6f78b0] [c000000000da196c] inet_lhash2_lookup+0x1fc/0x210 [ 3062.666684] [c0000007ff6f7930] [c000000000da215c] __inet_lookup_listener+0x1ec/0x1f0 [ 3062.666914] [c0000007ff6f7a00] [c000000000dcff60] tcp_v4_rcv+0x800/0xd00 [ 3062.666938] [c0000007ff6f7b20] [c000000000d94988] ip_protocol_deliver_rcu+0x68/0x2d0 [ 3062.666965] [c0000007ff6f7b70] [c000000000d94c60] ip_local_deliver_finish+0x70/0x90 [ 3062.666991] [c0000007ff6f7b90] [c000000000d94d1c] ip_local_deliver+0x9c/0x130 [ 3062.667174] [c0000007ff6f7c00] [c000000000d94058] ip_rcv_finish+0xc8/0x100 [ 3062.667198] [c0000007ff6f7c40] [c000000000d94ec0] ip_rcv+0x110/0x120 [ 3062.667223] [c0000007ff6f7cc0] [c000000000ce0764] __netif_receive_skb_one_core+0x74/0xb0 [ 3062.667250] [c0000007ff6f7d10] [c000000000ce0b58] process_backlog+0xc8/0x200 [ 3062.667317] [c0000007ff6f7d80] [c000000000ce311c] net_rx_action+0x1ec/0x540 [ 3062.667452] [c0000007ff6f7ea0] [c000000000f1f518] __do_softirq+0x158/0x3c4 [ 3062.667478] [c0000007ff6f7f90] [c000000000032fa8] call_do_softirq+0x14/0x24 [ 3062.667503] [c000000668043790] [c00000000001d928] do_softirq_own_stack+0x38/0x50 [ 3062.667531] [c0000006680437b0] [c00000000014e010] do_softirq.part.17+0x80/0xb0 [ 3062.667713] [c0000006680437e0] [c00000000014e11c] __local_bh_enable_ip+0xdc/0xf0 [ 3062.667739] [c000000668043800] [c000000000d99e68] ip_finish_output2+0x1e8/0x710 [ 3062.667766] [c0000006680438a0] [c000000000d9c4c4] ip_output+0xd4/0x190 [ 3062.667790] [c000000668043930] [c000000000d9b948] ip_local_out+0x68/0x90 [ 3062.667887] [c000000668043970] [c000000000d9bd50] __ip_queue_xmit+0x170/0x4a0 [ 3062.667992] [c000000668043a00] [c000000000dca81c] ip_queue_xmit+0x1c/0x30 [ 3062.668016] [c000000668043a20] [c000000000dc1e34] __tcp_transmit_skb+0x604/0xd80 [ 3062.668043] [c000000668043ad0] [c000000000dc3208] tcp_connect+0xc58/0x10a0 [ 3062.668258] [c000000668043bc0] [c000000000dccb98] tcp_v4_connect+0x478/0x5b0 [ 3062.668812] [c000000668043c50] [c000000000df22b0] __inet_stream_connect+0x160/0x4f0 [ 3062.669144] [c000000668043cf0] [c000000000df269c] inet_stream_connect+0x5c/0x90 [ 3062.669404] [c000000668043d30] [c000000000cab098] __sys_connect+0xb8/0x160 [ 3062.669662] [c000000668043e00] [c000000000cab168] sys_connect+0x28/0x40 [ 3062.669932] [c000000668043e20] [c00000000000b378] system_call+0x5c/0x68 [ 3062.670460] Instruction dump: [ 3062.670479] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX [ 3062.671011] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX [ 3062.690989] ---[ end trace e0c764d7ab8c7cc2 ]--- [ 3062.856563] [ 3063.856744] Kernel panic - not syncing: Aiee, killing interrupt handler!