From: Gal Pressman Date: Sun, 9 Nov 2025 09:37:52 +0000 (+0200) Subject: net/mlx5e: Fix wraparound in rate limiting for values above 255 Gbps X-Git-Tag: v6.18-rc6~31^2~9^2~1 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=43b27d1bd88a4bce34ec2437d103acfae9655f9e;p=thirdparty%2Flinux.git net/mlx5e: Fix wraparound in rate limiting for values above 255 Gbps Add validation to reject rates exceeding 255 Gbps that would overflow the 8 bits max bandwidth field. Fixes: d8880795dabf ("net/mlx5e: Implement DCBNL IEEE max rate") Signed-off-by: Gal Pressman Reviewed-by: Nimrod Oren Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/1762681073-1084058-5-git-send-email-tariqt@nvidia.com Signed-off-by: Paolo Abeni --- diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c index 345614471052..d88a48210fdc 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c @@ -596,11 +596,13 @@ static int mlx5e_dcbnl_ieee_setmaxrate(struct net_device *netdev, u8 max_bw_value[IEEE_8021QAZ_MAX_TCS]; u8 max_bw_unit[IEEE_8021QAZ_MAX_TCS]; __u64 upper_limit_mbps; + __u64 upper_limit_gbps; int i; memset(max_bw_value, 0, sizeof(max_bw_value)); memset(max_bw_unit, 0, sizeof(max_bw_unit)); upper_limit_mbps = 255 * MLX5E_100MB; + upper_limit_gbps = 255 * MLX5E_1GB; for (i = 0; i <= mlx5_max_tc(mdev); i++) { if (!maxrate->tc_maxrate[i]) { @@ -612,10 +614,16 @@ static int mlx5e_dcbnl_ieee_setmaxrate(struct net_device *netdev, MLX5E_100MB); max_bw_value[i] = max_bw_value[i] ? max_bw_value[i] : 1; max_bw_unit[i] = MLX5_100_MBPS_UNIT; - } else { + } else if (max_bw_value[i] <= upper_limit_gbps) { max_bw_value[i] = div_u64(maxrate->tc_maxrate[i], MLX5E_1GB); max_bw_unit[i] = MLX5_GBPS_UNIT; + } else { + netdev_err(netdev, + "tc_%d maxrate %llu Kbps exceeds limit %llu\n", + i, maxrate->tc_maxrate[i], + upper_limit_gbps); + return -EINVAL; } }