Commit 43b27d1b authored by Gal Pressman's avatar Gal Pressman Committed by Paolo Abeni
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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: d8880795 ("net/mlx5e: Implement DCBNL IEEE max rate")
Signed-off-by: default avatarGal Pressman <gal@nvidia.com>
Reviewed-by: default avatarNimrod Oren <noren@nvidia.com>
Signed-off-by: default avatarTariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1762681073-1084058-5-git-send-email-tariqt@nvidia.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent a7bf4d50

drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c

+9 −1
Original line number Diff line number Diff line
@@ -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;

		}

	}