[PATCH AUTOSEL 4.14 006/123] net/mlx5: Avoid panic when setting vport rate

Sasha Levin
2019-03-27T18:16:43Z

From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

[ Upstream commit 24319258660a84dd77f4be026a55b10a12524919 ]

If we try to set VFs rate on a VF (not PF) net device, the kernel
will be crash. The commands are show as below:

$ echo 2 > /sys/class/net/$MLX_PF0/device/sriov_numvfs
$ ip link set $MLX_VF0 vf 0 max_tx_rate 2 min_tx_rate 1

If not applied the first patch ("net/mlx5: Avoid panic when setting
vport mac, getting vport config"), the command:

$ ip link set $MLX_VF0 vf 0 rate 100

can also crash the kernel.

[ 1650.006388] RIP: 0010:mlx5_eswitch_set_vport_rate+0x1f/0x260 [mlx5_core]
[ 1650.007092] do_setlink+0x982/0xd20
[ 1650.007129] __rtnl_newlink+0x528/0x7d0
[ 1650.007374] rtnl_newlink+0x43/0x60
[ 1650.007407] rtnetlink_rcv_msg+0x2a2/0x320
[ 1650.007484] netlink_rcv_skb+0xcb/0x100
[ 1650.007519] netlink_unicast+0x17f/0x230
[ 1650.007554] netlink_sendmsg+0x2d2/0x3d0
[ 1650.007592] sock_sendmsg+0x36/0x50
[ 1650.007625] ___sys_sendmsg+0x280/0x2a0
[ 1650.007963] __sys_sendmsg+0x58/0xa0
[ 1650.007998] do_syscall_64+0x5b/0x180
[ 1650.009438] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: c9497c98901c ("net/mlx5: Add support for setting VF min rate")
Cc: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
index 2f93e6e9dc9e..2aec0c021b6c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
@@ -1966,19 +1966,24 @@ static int normalize_vports_min_rate(struct mlx5_eswitch *esw, u32 divider)
int mlx5_eswitch_set_vport_rate(struct mlx5_eswitch *esw, int vport,
u32 max_rate, u32 min_rate)
{
- u32 fw_max_bw_share = MLX5_CAP_QOS(esw->dev, max_tsar_bw_share);
- bool min_rate_supported = MLX5_CAP_QOS(esw->dev, esw_bw_share) &&
- fw_max_bw_share >= MLX5_MIN_BW_SHARE;
- bool max_rate_supported = MLX5_CAP_QOS(esw->dev, esw_rate_limit);
struct mlx5_vport *evport;
+ u32 fw_max_bw_share;
u32 previous_min_rate;
u32 divider;
+ bool min_rate_supported;
+ bool max_rate_supported;
int err = 0;

if (!ESW_ALLOWED(esw))
return -EPERM;
if (!LEGAL_VPORT(esw, vport))
return -EINVAL;
+
+ fw_max_bw_share = MLX5_CAP_QOS(esw->dev, max_tsar_bw_share);
+ min_rate_supported = MLX5_CAP_QOS(esw->dev, esw_bw_share) &&
+ fw_max_bw_share >= MLX5_MIN_BW_SHARE;
+ max_rate_supported = MLX5_CAP_QOS(esw->dev, esw_rate_limit);
+
if ((min_rate && !min_rate_supported) || (max_rate && !max_rate_supported))
return -EOPNOTSUPP;

--
2.19.1