> -----Original Message-----
> From: linux-kernel-owner@xxxxxxxxxxxxxxx <linux-kernel-
> owner@xxxxxxxxxxxxxxx> On Behalf Of Parav Pandit
> Sent: Monday, July 29, 2019 10:55 AM
> To: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>; leon@xxxxxxxxxx;
> dledford@xxxxxxxxxx; jgg@xxxxxxxx
> Cc: linux-rdma@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: RE: [BUG] infiniband: mlx5: a possible null-pointer dereference in
> set_roce_addr()
>
> Hi Jia,
>
> > -----Original Message-----
> > From: linux-rdma-owner@xxxxxxxxxxxxxxx <linux-rdma-
> > owner@xxxxxxxxxxxxxxx> On Behalf Of Jia-Ju Bai
> > Sent: Monday, July 29, 2019 7:47 AM
> > To: leon@xxxxxxxxxx; dledford@xxxxxxxxxx; jgg@xxxxxxxx
> > Cc: linux-rdma@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: [BUG] infiniband: mlx5: a possible null-pointer dereference
> > in
> > set_roce_addr()
> >
> > In set_roce_addr(), there is an if statement on line 589 to check
> > whether gid is
> > NULL:
> > if (gid)
> >
> > When gid is NULL, it is used on line 613:
> > return mlx5_core_roce_gid_set(..., gid->raw, ...);
> >
> > Thus, a possible null-pointer dereference may occur.
> >
> > This bug is found by a static analysis tool STCheck written by us.
> >
> While static checker is right, it is not a real bug, because gid->raw pointer
> points to GID entry itself so when GID is NULL, gid->raw is NULL too.
>
> One way to suppress the static checker warning/error is below patch.
> Will let Leon review it.
>
> > I do not know how to correctly fix this bug, so I only report it.
> >
> >
> > Best wishes,
> > Jia-Ju Bai
>
> From 30e055dba77e595bf88aebd3a9c75ed76bc9c65a Mon Sep 17 00:00:00
> 2001
> From: Parav Pandit <parav@xxxxxxxxxxxx>
> Date: Mon, 29 Jul 2019 00:13:21 -0500
> Subject: [PATCH] IB/mlx5: Avoid static checker warning for NULL access
>
> union ib_gid *gid and gid->raw pointers refers to the same address.
> However some static checker reports this as possible NULL access warning in
> call to mlx5_core_roce_gid_set().
>
> To suppress such warning, instead of working on raw GID element, expose API
> using union ib_gid*.
>
> Reported-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
> ---
> drivers/infiniband/hw/mlx5/main.c | 2 +-
> drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c | 12 +++++++-----
> drivers/net/ethernet/mellanox/mlx5/core/lib/gid.c | 5 +++--
> drivers/net/ethernet/mellanox/mlx5/core/rdma.c | 2 +-
> include/linux/mlx5/driver.h | 4 +++-
> 5 files changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/infiniband/hw/mlx5/main.c
> b/drivers/infiniband/hw/mlx5/main.c
> index c2a5780cb394..e60785bad7ef 100644
> --- a/drivers/infiniband/hw/mlx5/main.c
> +++ b/drivers/infiniband/hw/mlx5/main.c
> @@ -610,7 +610,7 @@ static int set_roce_addr(struct mlx5_ib_dev *dev, u8
> port_num,
> }
>
> return mlx5_core_roce_gid_set(dev->mdev, index, roce_version,
> - roce_l3_type, gid->raw, mac,
> + roce_l3_type, &gid, mac,
> vlan_id < VLAN_CFI_MASK, vlan_id,
> port_num);
> }
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c
> b/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c
> index 4c50efe4e7f1..76b8236af9c7 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c
> @@ -850,6 +850,7 @@ struct mlx5_fpga_conn *mlx5_fpga_conn_create(struct
> mlx5_fpga_device *fdev,
> enum mlx5_ifc_fpga_qp_type
> qp_type) {
> struct mlx5_fpga_conn *ret, *conn;
> + struct ib_gid remote_gid = {};
> u8 *remote_mac, *remote_ip;
> int err;
>
> @@ -876,11 +877,12 @@ struct mlx5_fpga_conn
> *mlx5_fpga_conn_create(struct mlx5_fpga_device *fdev,
> goto err;
> }
>
> - /* Build Modified EUI-64 IPv6 address from the MAC address */
> remote_ip = MLX5_ADDR_OF(fpga_qpc, conn->fpga_qpc, remote_ip);
> - remote_ip[0] = 0xfe;
> - remote_ip[1] = 0x80;
> - addrconf_addr_eui48(&remote_ip[8], remote_mac);
> + memcpy(remote_gid.raw[0], remote_ip, sizeof(remote_gid.raw));
> + /* Build Modified EUI-64 IPv6 address from the MAC address */
> + remte_gid.raw[0] = 0xfe;
> + remte_gid.raw[1] = 0x80;
> + addrconf_addr_eui48(&remote_gid.raw[8], remote_mac);
>
> err = mlx5_core_reserved_gid_alloc(fdev->mdev, &conn-
> >qp.sgid_index);
> if (err) {
> @@ -892,7 +894,7 @@ struct mlx5_fpga_conn *mlx5_fpga_conn_create(struct
> mlx5_fpga_device *fdev,
> err = mlx5_core_roce_gid_set(fdev->mdev, conn->qp.sgid_index,
> MLX5_ROCE_VERSION_2,
> MLX5_ROCE_L3_TYPE_IPV6,
> - remote_ip, remote_mac, true, 0,
> + &remote_gid, remote_mac, true, 0,
> MLX5_FPGA_PORT_NUM);
> if (err) {
> mlx5_fpga_err(fdev, "Failed to set SGID: %d\n", err); diff --git
> a/drivers/net/ethernet/mellanox/mlx5/core/lib/gid.c
> b/drivers/net/ethernet/mellanox/mlx5/core/lib/gid.c
> index 7722a3f9bb68..9b8563a2bd50 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/gid.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/gid.c
> @@ -120,7 +120,8 @@ unsigned int mlx5_core_reserved_gids_count(struct
> mlx5_core_dev *dev)
> EXPORT_SYMBOL_GPL(mlx5_core_reserved_gids_count);
>
> int mlx5_core_roce_gid_set(struct mlx5_core_dev *dev, unsigned int index,
> - u8 roce_version, u8 roce_l3_type, const u8 *gid,
> + u8 roce_version, u8 roce_l3_type,
> + const union ib_gid *gid,
> const u8 *mac, bool vlan, u16 vlan_id, u8 port_num)
> { #define MLX5_SET_RA(p, f, v) MLX5_SET(roce_addr_layout, p, f, v) @@ -
> 145,7 +146,7 @@ int mlx5_core_roce_gid_set(struct mlx5_core_dev *dev,
> unsigned int index,
> ether_addr_copy(addr_mac, mac);
> MLX5_SET_RA(in_addr, roce_version, roce_version);
> MLX5_SET_RA(in_addr, roce_l3_type, roce_l3_type);
> - memcpy(addr_l3_addr, gid, gidsz);
> + memcpy(addr_l3_addr, &gid->raw[0], gidsz);
> }
>
> if (MLX5_CAP_GEN(dev, num_vhca_ports) > 0) diff --git
> a/drivers/net/ethernet/mellanox/mlx5/core/rdma.c
> b/drivers/net/ethernet/mellanox/mlx5/core/rdma.c
> index 17ce9dd56b13..2a4467346231 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/rdma.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/rdma.c
> @@ -139,7 +139,7 @@ static int mlx5_rdma_add_roce_addr(struct
> mlx5_core_dev *dev)
> mlx5_rdma_make_default_gid(dev, &gid);
> return mlx5_core_roce_gid_set(dev, 0,
> MLX5_ROCE_VERSION_1,
> - 0, gid.raw, mac,
> + 0, &gid, mac,
> false, 0, 1);
> }
>
> diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index
> 1e42c13819ae..691864e853be 100644
> --- a/include/linux/mlx5/driver.h
> +++ b/include/linux/mlx5/driver.h
> @@ -47,6 +47,7 @@
> #include <linux/interrupt.h>
> #include <linux/idr.h>
> #include <linux/notifier.h>
> +#include <rdma/ib_verbs.h>
>
> #include <linux/mlx5/device.h>
> #include <linux/mlx5/doorbell.h>
> @@ -1002,7 +1003,8 @@ struct cpumask *
> mlx5_comp_irq_get_affinity_mask(struct mlx5_core_dev *dev, int vector);
> unsigned int mlx5_core_reserved_gids_count(struct mlx5_core_dev *dev); int
> mlx5_core_roce_gid_set(struct mlx5_core_dev *dev, unsigned int index,
> - u8 roce_version, u8 roce_l3_type, const u8 *gid,
> + u8 roce_version, u8 roce_l3_type,
> + const union ib_gid *gid,
> const u8 *mac, bool vlan, u16 vlan_id, u8 port_num);
>
> static inline int fw_initializing(struct mlx5_core_dev *dev)
> --
> 2.19.2
Leon just replied. Thanks.
