net/mlx5e: fix double free of encap_header

When mlx5_packet_reformat_alloc() fails, the encap_header allocated in
mlx5e_tc_tun_create_header_ipv4{6} will be released within it. However,
e->encap_header is already set to the previously freed encap_header
before mlx5_packet_reformat_alloc(). As a result, the later
mlx5e_encap_put() will free e->encap_header again, causing a double free
issue.

mlx5e_encap_put()
    --> mlx5e_encap_dealloc()
        --> kfree(e->encap_header)

This happens when cmd: MLX5_CMD_OP_ALLOC_PACKET_REFORMAT_CONTEXT fail.

This patch fix it by not setting e->encap_header until
mlx5_packet_reformat_alloc() success.

Fixes: d589e785baf5e ("net/mlx5e: Allow concurrent creation of encap entries")
Reported-by: Cruz Zhao <cruzzhao@linux.alibaba.com>
Reported-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
index 00a04fdd756f570f8a9db368eb1685f9d5df9a8e..8bca696b6658c46901f16be770f6456d4f506e84 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
@@ -300,9 +300,6 @@ int mlx5e_tc_tun_create_header_ipv4(struct mlx5e_priv *priv,
        if (err)
                goto destroy_neigh_entry;
 
-       e->encap_size = ipv4_encap_size;
-       e->encap_header = encap_header;
-
        if (!(nud_state & NUD_VALID)) {
                neigh_event_send(attr.n, NULL);
                /* the encap entry will be made valid on neigh update event
@@ -322,6 +319,8 @@ int mlx5e_tc_tun_create_header_ipv4(struct mlx5e_priv *priv,
                goto destroy_neigh_entry;
        }
 
+       e->encap_size = ipv4_encap_size;
+       e->encap_header = encap_header;
        e->flags |= MLX5_ENCAP_ENTRY_VALID;
        mlx5e_rep_queue_neigh_stats_work(netdev_priv(attr.out_dev));
        mlx5e_route_lookup_ipv4_put(&attr);
@@ -568,9 +567,6 @@ int mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv,
        if (err)
                goto destroy_neigh_entry;
 
-       e->encap_size = ipv6_encap_size;
-       e->encap_header = encap_header;
-
        if (!(nud_state & NUD_VALID)) {
                neigh_event_send(attr.n, NULL);
                /* the encap entry will be made valid on neigh update event
@@ -590,6 +586,8 @@ int mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv,
                goto destroy_neigh_entry;
        }
 
+       e->encap_size = ipv6_encap_size;
+       e->encap_header = encap_header;
        e->flags |= MLX5_ENCAP_ENTRY_VALID;
        mlx5e_rep_queue_neigh_stats_work(netdev_priv(attr.out_dev));
        mlx5e_route_lookup_ipv6_put(&attr);