From: Paul Blakey paulb@nvidia.com
[ Upstream commit 89e394675818bde8e30e135611c506455fa03fb7 ]
Currently, if a neighbour isn't valid when offloading tunnel encap rules, we offload the original match and replace the original action with "goto slow path" action. For this we use a temporary flow attribute based on the original flow attribute and then change the action. Flow flags, which among those is the CT flag, are still shared for the slow path rule offload, so we end up parsing this flow as a CT + goto slow path rule.
Besides being unnecessary, CT action offload saves extra information in the passed flow attribute, such as created ct_flow and mod_hdr, which is lost onces the temporary flow attribute is freed.
When a neigh is updated and is valid, we offload the original CT rule with original CT action, which again creates a ct_flow and mod_hdr and saves it in the flow's original attribute. Then we delete the slow path rule with a temporary flow attribute based on original updated flow attribute, and we free the relevant ct_flow and mod_hdr.
Then when tc deletes this flow, we try to free the ct_flow and mod_hdr on the flow's attribute again.
To fix the issue, skip all furture proccesing (CT/Sample/Split rules) in offload/unoffload of slow path rules.
Call trace: [ 758.850525] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000218 [ 758.952987] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 758.964170] Modules linked in: act_csum(E) act_pedit(E) act_tunnel_key(E) act_ct(E) nf_flow_table(E) xt_nat(E) ip6table_filter(E) ip6table_nat(E) xt_comment(E) ip6_tables(E) xt_conntrack(E) xt_MASQUERADE(E) nf_conntrack_netlink(E) xt_addrtype(E) iptable_filter(E) iptable_nat(E) bpfilter(E) br_netfilter(E) bridge(E) stp(E) llc(E) xfrm_user(E) overlay(E) act_mirred(E) act_skbedit(E) rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) esp6_offload(E) esp6(E) esp4_offload(E) esp4(E) xfrm_algo(E) mlx5_ib(OE) ib_uverbs(OE) geneve(E) ip6_udp_tunnel(E) udp_tunnel(E) nfnetlink_cttimeout(E) nfnetlink(E) mlx5_core(OE) act_gact(E) cls_flower(E) sch_ingress(E) openvswitch(E) nsh(E) nf_conncount(E) nf_nat(E) mlxfw(OE) psample(E) nf_conntrack(E) nf_defrag_ipv4(E) vfio_mdev(E) mdev(E) ib_core(OE) mlx_compat(OE) crct10dif_ce(E) uio_pdrv_genirq(E) uio(E) i2c_mlx(E) mlxbf_pmc(E) sbsa_gwdt(E) mlxbf_gige(E) gpio_mlxbf2(E) mlxbf_pka(E) mlx_trio(E) mlx_bootctl(E) bluefield_edac(E) knem(O) [ 758.964225] ip_tables(E) mlxbf_tmfifo(E) ipv6(E) crc_ccitt(E) nf_defrag_ipv6(E) [ 759.154186] CPU: 5 PID: 122 Comm: kworker/u16:1 Tainted: G OE 5.4.60-mlnx.52.gde81e85 #1 [ 759.172870] Hardware name: https://www.mellanox.com BlueField SoC/BlueField SoC, BIOS BlueField:3.5.0-2-gc1b5d64 Jan 4 2021 [ 759.195466] Workqueue: mlx5e mlx5e_rep_neigh_update [mlx5_core] [ 759.207344] pstate: a0000005 (NzCv daif -PAN -UAO) [ 759.217003] pc : mlx5_del_flow_rules+0x5c/0x160 [mlx5_core] [ 759.228229] lr : mlx5_del_flow_rules+0x34/0x160 [mlx5_core] [ 759.405858] Call trace: [ 759.410804] mlx5_del_flow_rules+0x5c/0x160 [mlx5_core] [ 759.421337] __mlx5_eswitch_del_rule.isra.43+0x5c/0x1c8 [mlx5_core] [ 759.433963] mlx5_eswitch_del_offloaded_rule_ct+0x34/0x40 [mlx5_core] [ 759.446942] mlx5_tc_rule_delete_ct+0x68/0x74 [mlx5_core] [ 759.457821] mlx5_tc_ct_delete_flow+0x160/0x21c [mlx5_core] [ 759.469051] mlx5e_tc_unoffload_fdb_rules+0x158/0x168 [mlx5_core] [ 759.481325] mlx5e_tc_encap_flows_del+0x140/0x26c [mlx5_core] [ 759.492901] mlx5e_rep_update_flows+0x11c/0x1ec [mlx5_core] [ 759.504127] mlx5e_rep_neigh_update+0x160/0x200 [mlx5_core] [ 759.515314] process_one_work+0x178/0x400 [ 759.523350] worker_thread+0x58/0x3e8 [ 759.530685] kthread+0x100/0x12c [ 759.537152] ret_from_fork+0x10/0x18 [ 759.544320] Code: 97ffef55 51000673 3100067f 54ffff41 (b9421ab3) [ 759.556548] ---[ end trace fab818bb1085832d ]---
Fixes: 4c3844d9e97e ("net/mlx5e: CT: Introduce connection tracking") Signed-off-by: Paul Blakey paulb@nvidia.com Reviewed-by: Roi Dayan roid@nvidia.com Reviewed-by: Vlad Buslov vladbu@nvidia.com Signed-off-by: Saeed Mahameed saeedm@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c index 3be34b1128731..4b8a442f09cd6 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -1165,6 +1165,9 @@ mlx5e_tc_offload_fdb_rules(struct mlx5_eswitch *esw, struct mlx5e_tc_mod_hdr_acts *mod_hdr_acts; struct mlx5_flow_handle *rule;
+ if (attr->flags & MLX5_ESW_ATTR_FLAG_SLOW_PATH) + return mlx5_eswitch_add_offloaded_rule(esw, spec, attr); + if (flow_flag_test(flow, CT)) { mod_hdr_acts = &attr->parse_attr->mod_hdr_acts;
@@ -1195,6 +1198,9 @@ mlx5e_tc_unoffload_fdb_rules(struct mlx5_eswitch *esw, { flow_flag_clear(flow, OFFLOADED);
+ if (attr->flags & MLX5_ESW_ATTR_FLAG_SLOW_PATH) + goto offload_rule_0; + if (flow_flag_test(flow, CT)) { mlx5_tc_ct_delete_flow(get_ct_priv(flow->priv), flow, attr); return; @@ -1203,6 +1209,7 @@ mlx5e_tc_unoffload_fdb_rules(struct mlx5_eswitch *esw, if (attr->esw_attr->split_count) mlx5_eswitch_del_fwd_rule(esw, flow->rule[1], attr);
+offload_rule_0: mlx5_eswitch_del_offloaded_rule(esw, flow->rule[0], attr); }