On Wed, Oct 25, 2023 at 11:06:25AM +0200, Wojciech Drewek wrote:
>
>
>On 25.10.2023 05:27, Dust Li wrote:
>> 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)
>
>nit: I think it should mlx5e_encap_put_locked not mlx5e_encap_put to be precise.
You are right.
The original version is mlx5e_encap_put, I mistakenly used the name of
the old version when doing git blame.
Best regards,
Dust
>
>>
>> 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@xxxxxxxxxxxxxxxxx>
>> Reported-by: Tianchen Ding <dtcccc@xxxxxxxxxxxxxxxxx>
>> Signed-off-by: Dust Li <dust.li@xxxxxxxxxxxxxxxxx>
>> ---
>
>Reviewed-by: Wojciech Drewek <wojciech.drewek@xxxxxxxxx>
>
>> drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 10 ++++------
>> 1 file changed, 4 insertions(+), 6 deletions(-)
>>
>> 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 00a04fdd756f..8bca696b6658 100644
>> --- 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);
