Commit 554fe75c authored by Dmytro Linkin's avatar Dmytro Linkin Committed by Saeed Mahameed

net/mlx5e: Avoid duplicating rule destinations

Following scenario easily break driver logic and crash the kernel:
1. Add rule with mirred actions to same device.
2. Delete this rule.
In described scenario rule is not added to database and on deletion
driver access invalid entry.
Example:

 $ tc filter add dev ens1f0_0 ingress protocol ip prio 1 \
       flower skip_sw \
       action mirred egress mirror dev ens1f0_1 pipe \
       action mirred egress redirect dev ens1f0_1
 $ tc filter del dev ens1f0_0 ingress protocol ip prio 1

Dmesg output:

[  376.634396] mlx5_core 0000:82:00.0: mlx5_cmd_check:756:(pid 3439): DESTROY_FLOW_GROUP(0x934) op_mod(0x0) failed, status bad resource state(0x9), syndrome (0x563e2f)
[  376.654983] mlx5_core 0000:82:00.0: del_hw_flow_group:567:(pid 3439): flow steering can't destroy fg 89 of ft 3145728
[  376.673433] kasan: CONFIG_KASAN_INLINE enabled
[  376.683769] kasan: GPF could be caused by NULL-ptr deref or user memory access
[  376.695229] general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI
[  376.705069] CPU: 7 PID: 3439 Comm: tc Not tainted 5.4.0-rc5+ #76
[  376.714959] Hardware name: Supermicro SYS-2028TP-DECTR/X10DRT-PT, BIOS 2.0a 08/12/2016
[  376.726371] RIP: 0010:mlx5_del_flow_rules+0x105/0x960 [mlx5_core]
[  376.735817] Code: 01 00 00 00 48 83 eb 08 e8 28 d9 ff ff 4c 39 e3 75 d8 4c 8d bd c0 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 84 04 00 00 48 8d 7d 28 8b 9 d
[  376.761261] RSP: 0018:ffff888847c56db8 EFLAGS: 00010202
[  376.770054] RAX: dffffc0000000000 RBX: ffff8888582a6da0 RCX: ffff888847c56d60
[  376.780743] RDX: 0000000000000058 RSI: 0000000000000008 RDI: 0000000000000282
[  376.791328] RBP: 0000000000000000 R08: fffffbfff0c60ea6 R09: fffffbfff0c60ea6
[  376.802050] R10: fffffbfff0c60ea5 R11: ffffffff8630752f R12: ffff8888582a6da0
[  376.812798] R13: dffffc0000000000 R14: ffff8888582a6da0 R15: 00000000000002c0
[  376.823445] FS:  00007f675f9a8840(0000) GS:ffff88886d200000(0000) knlGS:0000000000000000
[  376.834971] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  376.844179] CR2: 00000000007d9640 CR3: 00000007d3f26003 CR4: 00000000001606e0
[  376.854843] Call Trace:
[  376.868542]  __mlx5_eswitch_del_rule+0x49/0x300 [mlx5_core]
[  376.877735]  mlx5e_tc_del_fdb_flow+0x6ec/0x9e0 [mlx5_core]
[  376.921549]  mlx5e_flow_put+0x2b/0x50 [mlx5_core]
[  376.929813]  mlx5e_delete_flower+0x5b6/0xbd0 [mlx5_core]
[  376.973030]  tc_setup_cb_reoffload+0x29/0xc0
[  376.980619]  fl_reoffload+0x50a/0x770 [cls_flower]
[  377.015087]  tcf_block_playback_offloads+0xbd/0x250
[  377.033400]  tcf_block_setup+0x1b2/0xc60
[  377.057247]  tcf_block_offload_cmd+0x195/0x240
[  377.098826]  tcf_block_offload_unbind+0xe7/0x180
[  377.107056]  __tcf_block_put+0xe5/0x400
[  377.114528]  ingress_destroy+0x3d/0x60 [sch_ingress]
[  377.122894]  qdisc_destroy+0xf1/0x5a0
[  377.129993]  qdisc_graft+0xa3d/0xe50
[  377.151227]  tc_get_qdisc+0x48e/0xa20
[  377.165167]  rtnetlink_rcv_msg+0x35d/0x8d0
[  377.199528]  netlink_rcv_skb+0x11e/0x340
[  377.219638]  netlink_unicast+0x408/0x5b0
[  377.239913]  netlink_sendmsg+0x71b/0xb30
[  377.267505]  sock_sendmsg+0xb1/0xf0
[  377.273801]  ___sys_sendmsg+0x635/0x900
[  377.312784]  __sys_sendmsg+0xd3/0x170
[  377.338693]  do_syscall_64+0x95/0x460
[  377.344833]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  377.352321] RIP: 0033:0x7f675e58e090

To avoid this, for every mirred action check if output device was
already processed. If so - drop rule with EOPNOTSUPP error.
Signed-off-by: default avatarDmytro Linkin <dmitrolin@mellanox.com>
Reviewed-by: default avatarRoi Dayan <roid@mellanox.com>
Reviewed-by: default avatarVlad Buslov <vladbu@mellanox.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
parent d76063c5
......@@ -2999,6 +2999,25 @@ static struct ip_tunnel_info *dup_tun_info(const struct ip_tunnel_info *tun_info
return kmemdup(tun_info, tun_size, GFP_KERNEL);
}
static bool is_duplicated_encap_entry(struct mlx5e_priv *priv,
struct mlx5e_tc_flow *flow,
int out_index,
struct mlx5e_encap_entry *e,
struct netlink_ext_ack *extack)
{
int i;
for (i = 0; i < out_index; i++) {
if (flow->encaps[i].e != e)
continue;
NL_SET_ERR_MSG_MOD(extack, "can't duplicate encap action");
netdev_err(priv->netdev, "can't duplicate encap action\n");
return true;
}
return false;
}
static int mlx5e_attach_encap(struct mlx5e_priv *priv,
struct mlx5e_tc_flow *flow,
struct net_device *mirred_dev,
......@@ -3034,6 +3053,12 @@ static int mlx5e_attach_encap(struct mlx5e_priv *priv,
/* must verify if encap is valid or not */
if (e) {
/* Check that entry was not already attached to this flow */
if (is_duplicated_encap_entry(priv, flow, out_index, e, extack)) {
err = -EOPNOTSUPP;
goto out_err;
}
mutex_unlock(&esw->offloads.encap_tbl_lock);
wait_for_completion(&e->res_ready);
......@@ -3220,6 +3245,26 @@ bool mlx5e_is_valid_eswitch_fwd_dev(struct mlx5e_priv *priv,
same_hw_devs(priv, netdev_priv(out_dev));
}
static bool is_duplicated_output_device(struct net_device *dev,
struct net_device *out_dev,
int *ifindexes, int if_count,
struct netlink_ext_ack *extack)
{
int i;
for (i = 0; i < if_count; i++) {
if (ifindexes[i] == out_dev->ifindex) {
NL_SET_ERR_MSG_MOD(extack,
"can't duplicate output to same device");
netdev_err(dev, "can't duplicate output to same device: %s\n",
out_dev->name);
return true;
}
}
return false;
}
static int parse_tc_fdb_actions(struct mlx5e_priv *priv,
struct flow_action *flow_action,
struct mlx5e_tc_flow *flow,
......@@ -3231,11 +3276,12 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv,
struct mlx5e_tc_flow_parse_attr *parse_attr = attr->parse_attr;
struct mlx5e_rep_priv *rpriv = priv->ppriv;
const struct ip_tunnel_info *info = NULL;
int ifindexes[MLX5_MAX_FLOW_FWD_VPORTS];
bool ft_flow = mlx5e_is_ft_flow(flow);
const struct flow_action_entry *act;
int err, i, if_count = 0;
bool encap = false;
u32 action = 0;
int err, i;
if (!flow_action_has_entries(flow_action))
return -EINVAL;
......@@ -3312,6 +3358,16 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv,
struct net_device *uplink_dev = mlx5_eswitch_uplink_get_proto_dev(esw, REP_ETH);
struct net_device *uplink_upper;
if (is_duplicated_output_device(priv->netdev,
out_dev,
ifindexes,
if_count,
extack))
return -EOPNOTSUPP;
ifindexes[if_count] = out_dev->ifindex;
if_count++;
rcu_read_lock();
uplink_upper =
netdev_master_upper_dev_get_rcu(uplink_dev);
......
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