6.12-stable review patch. If anyone has any objections, please let me know.
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From: Jianbo Liu jianbol@nvidia.com
[ Upstream commit 6b4be64fd9fec16418f365c2d8e47a7566e9eba5 ]
The function mlx5_uplink_netdev_get() gets the uplink netdevice pointer from mdev->mlx5e_res.uplink_netdev. However, the netdevice can be removed and its pointer cleared when unbound from the mlx5_core.eth driver. This results in a NULL pointer, causing a kernel panic.
BUG: unable to handle page fault for address: 0000000000001300 at RIP: 0010:mlx5e_vport_rep_load+0x22a/0x270 [mlx5_core] Call Trace: <TASK> mlx5_esw_offloads_rep_load+0x68/0xe0 [mlx5_core] esw_offloads_enable+0x593/0x910 [mlx5_core] mlx5_eswitch_enable_locked+0x341/0x420 [mlx5_core] mlx5_devlink_eswitch_mode_set+0x17e/0x3a0 [mlx5_core] devlink_nl_eswitch_set_doit+0x60/0xd0 genl_family_rcv_msg_doit+0xe0/0x130 genl_rcv_msg+0x183/0x290 netlink_rcv_skb+0x4b/0xf0 genl_rcv+0x24/0x40 netlink_unicast+0x255/0x380 netlink_sendmsg+0x1f3/0x420 __sock_sendmsg+0x38/0x60 __sys_sendto+0x119/0x180 do_syscall_64+0x53/0x1d0 entry_SYSCALL_64_after_hwframe+0x4b/0x53
Ensure the pointer is valid before use by checking it for NULL. If it is valid, immediately call netdev_hold() to take a reference, and preventing the netdevice from being freed while it is in use.
Fixes: 7a9fb35e8c3a ("net/mlx5e: Do not reload ethernet ports when changing eswitch mode") Signed-off-by: Jianbo Liu jianbol@nvidia.com Reviewed-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Jiri Pirko jiri@nvidia.com Reviewed-by: Dragos Tatulea dtatulea@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Link: https://patch.msgid.link/1757939074-617281-2-git-send-email-tariqt@nvidia.co... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/mellanox/mlx5/core/en_rep.c | 27 +++++++++++++++---- .../net/ethernet/mellanox/mlx5/core/esw/qos.c | 1 + .../ethernet/mellanox/mlx5/core/lib/mlx5.h | 15 ++++++++++- include/linux/mlx5/driver.h | 1 + 4 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c index 18ec392d17404..b561358474c4f 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c @@ -1497,12 +1497,21 @@ static const struct mlx5e_profile mlx5e_uplink_rep_profile = { static int mlx5e_vport_uplink_rep_load(struct mlx5_core_dev *dev, struct mlx5_eswitch_rep *rep) { - struct mlx5e_priv *priv = netdev_priv(mlx5_uplink_netdev_get(dev)); struct mlx5e_rep_priv *rpriv = mlx5e_rep_to_rep_priv(rep); + struct net_device *netdev; + struct mlx5e_priv *priv; + int err; + + netdev = mlx5_uplink_netdev_get(dev); + if (!netdev) + return 0;
+ priv = netdev_priv(netdev); rpriv->netdev = priv->netdev; - return mlx5e_netdev_change_profile(priv, &mlx5e_uplink_rep_profile, - rpriv); + err = mlx5e_netdev_change_profile(priv, &mlx5e_uplink_rep_profile, + rpriv); + mlx5_uplink_netdev_put(dev, netdev); + return err; }
static void @@ -1629,8 +1638,16 @@ mlx5e_vport_rep_unload(struct mlx5_eswitch_rep *rep) { struct mlx5e_rep_priv *rpriv = mlx5e_rep_to_rep_priv(rep); struct net_device *netdev = rpriv->netdev; - struct mlx5e_priv *priv = netdev_priv(netdev); - void *ppriv = priv->ppriv; + struct mlx5e_priv *priv; + void *ppriv; + + if (!netdev) { + ppriv = rpriv; + goto free_ppriv; + } + + priv = netdev_priv(netdev); + ppriv = priv->ppriv;
if (rep->vport == MLX5_VPORT_UPLINK) { mlx5e_vport_uplink_rep_unload(rpriv); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c index 02a3563f51ad2..d8c304427e2ab 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c @@ -733,6 +733,7 @@ static u32 mlx5_esw_qos_lag_link_speed_get_locked(struct mlx5_core_dev *mdev) speed = lksettings.base.speed;
out: + mlx5_uplink_netdev_put(mdev, slave); return speed; }
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h b/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h index 37d5f445598c7..a7486e6d0d5ef 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h @@ -52,7 +52,20 @@ static inline struct net *mlx5_core_net(struct mlx5_core_dev *dev)
static inline struct net_device *mlx5_uplink_netdev_get(struct mlx5_core_dev *mdev) { - return mdev->mlx5e_res.uplink_netdev; + struct mlx5e_resources *mlx5e_res = &mdev->mlx5e_res; + struct net_device *netdev; + + mutex_lock(&mlx5e_res->uplink_netdev_lock); + netdev = mlx5e_res->uplink_netdev; + netdev_hold(netdev, &mlx5e_res->tracker, GFP_KERNEL); + mutex_unlock(&mlx5e_res->uplink_netdev_lock); + return netdev; +} + +static inline void mlx5_uplink_netdev_put(struct mlx5_core_dev *mdev, + struct net_device *netdev) +{ + netdev_put(netdev, &mdev->mlx5e_res.tracker); }
struct mlx5_sd; diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index da9749739abde..9a8eb644f6707 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -689,6 +689,7 @@ struct mlx5e_resources { bool tisn_valid; } hw_objs; struct net_device *uplink_netdev; + netdevice_tracker tracker; struct mutex uplink_netdev_lock; struct mlx5_crypto_dek_priv *dek_priv; };