The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From fe7738eb3ca3631a75844e790f6cb576c0fe7b00 Mon Sep 17 00:00:00 2001
From: Dima Chumak <dchumak@xxxxxxxxxx>
Date: Mon, 26 Apr 2021 15:16:26 +0300
Subject: [PATCH] net/mlx5e: Fix nullptr in mlx5e_tc_add_fdb_flow()
The result of __dev_get_by_index() is not checked for NULL, which then
passed to mlx5e_attach_encap() and gets dereferenced.
Also, in case of a successful lookup, the net_device reference count is
not incremented, which may result in net_device pointer becoming invalid
at any time during mlx5e_attach_encap() execution.
Fix by using dev_get_by_index(), which does proper reference counting on
the net_device pointer. Also, handle nullptr return value when mirred
device is not found.
It's safe to call dev_put() on the mirred net_device pointer, right
after mlx5e_attach_encap() call, because it's not being saved/copied
down the call chain.
Fixes: 3c37745ec614 ("net/mlx5e: Properly deal with encap flows add/del under neigh update")
Addresses-Coverity: ("Dereference null return value")
Signed-off-by: Dima Chumak <dchumak@xxxxxxxxxx>
Reviewed-by: Vlad Buslov <vladbu@xxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 46945d04b5b8..882bafba43f2 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -1322,10 +1322,10 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv,
struct netlink_ext_ack *extack)
{
struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
- struct net_device *out_dev, *encap_dev = NULL;
struct mlx5e_tc_flow_parse_attr *parse_attr;
struct mlx5_flow_attr *attr = flow->attr;
bool vf_tun = false, encap_valid = true;
+ struct net_device *encap_dev = NULL;
struct mlx5_esw_flow_attr *esw_attr;
struct mlx5_fc *counter = NULL;
struct mlx5e_rep_priv *rpriv;
@@ -1371,16 +1371,22 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv,
esw_attr = attr->esw_attr;
for (out_index = 0; out_index < MLX5_MAX_FLOW_FWD_VPORTS; out_index++) {
+ struct net_device *out_dev;
int mirred_ifindex;
if (!(esw_attr->dests[out_index].flags & MLX5_ESW_DEST_ENCAP))
continue;
mirred_ifindex = parse_attr->mirred_ifindex[out_index];
- out_dev = __dev_get_by_index(dev_net(priv->netdev),
- mirred_ifindex);
+ out_dev = dev_get_by_index(dev_net(priv->netdev), mirred_ifindex);
+ if (!out_dev) {
+ NL_SET_ERR_MSG_MOD(extack, "Requested mirred device not found");
+ err = -ENODEV;
+ goto err_out;
+ }
err = mlx5e_attach_encap(priv, flow, out_dev, out_index,
extack, &encap_dev, &encap_valid);
+ dev_put(out_dev);
if (err)
goto err_out;
