net: prestera: Add flex arrays to some structs

The "struct prestera_msg_vtcam_rule_add_req" uses a dynamically sized
set of trailing elements. Specifically, it uses an array of structures
of type "prestera_msg_acl_action actions_msg".

The "struct prestera_msg_flood_domain_ports_set_req" also uses a
dynamically sized set of trailing elements. Specifically, it uses an
array of structures of type "prestera_msg_acl_action actions_msg".

So, use the preferred way in the kernel declaring flexible arrays [1].

At the same time, prepare for the coming implementation by GCC and Clang
of the __counted_by attribute. Flexible array members annotated with
__counted_by can have their accesses bounds-checked at run-time via
CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for
strcpy/memcpy-family functions). In this case, it is important to note
that the attribute used is specifically __counted_by_le since the
counters are of type __le32.

The logic does not need to change since the counters for the flexible
arrays are asigned before any access to the arrays.

The order in which the structure prestera_msg_vtcam_rule_add_req and the
structure prestera_msg_flood_domain_ports_set_req are defined must be
changed to avoid incomplete type errors.

Also, avoid the open-coded arithmetic in memory allocator functions [2]
using the "struct_size" macro.

Moreover, the new structure members also allow us to avoid the open-
coded arithmetic on pointers. So, take advantage of this refactoring
accordingly.

This code was detected with the help of Coccinelle, and audited and
modified manually.

Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Erick Archer <erick.archer@outlook.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/AS8PR02MB7237E8469568A59795F1F0408BE12@AS8PR02MB7237.eurprd02.prod.outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_hw.c b/drivers/net/ethernet/marvell/prestera/prestera_hw.c
index fc6f7d2746e887157ab4ea978914be6c7b1de483..197198ba61b148c979a4f1328cc37f5aa8f9476d 100644 (file)
--- a/drivers/net/ethernet/marvell/prestera/prestera_hw.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_hw.c
@@ -419,15 +419,6 @@ struct prestera_msg_vtcam_destroy_req {
        __le32 vtcam_id;
 };
 
-struct prestera_msg_vtcam_rule_add_req {
-       struct prestera_msg_cmd cmd;
-       __le32 key[__PRESTERA_ACL_RULE_MATCH_TYPE_MAX];
-       __le32 keymask[__PRESTERA_ACL_RULE_MATCH_TYPE_MAX];
-       __le32 vtcam_id;
-       __le32 prio;
-       __le32 n_act;
-};
-
 struct prestera_msg_vtcam_rule_del_req {
        struct prestera_msg_cmd cmd;
        __le32 vtcam_id;
@@ -471,6 +462,16 @@ struct prestera_msg_acl_action {
        };
 };
 
+struct prestera_msg_vtcam_rule_add_req {
+       struct prestera_msg_cmd cmd;
+       __le32 key[__PRESTERA_ACL_RULE_MATCH_TYPE_MAX];
+       __le32 keymask[__PRESTERA_ACL_RULE_MATCH_TYPE_MAX];
+       __le32 vtcam_id;
+       __le32 prio;
+       __le32 n_act;
+       struct prestera_msg_acl_action actions_msg[] __counted_by_le(n_act);
+};
+
 struct prestera_msg_counter_req {
        struct prestera_msg_cmd cmd;
        __le32 client;
@@ -702,12 +703,6 @@ struct prestera_msg_flood_domain_destroy_req {
        __le32 flood_domain_idx;
 };
 
-struct prestera_msg_flood_domain_ports_set_req {
-       struct prestera_msg_cmd cmd;
-       __le32 flood_domain_idx;
-       __le32 ports_num;
-};
-
 struct prestera_msg_flood_domain_ports_reset_req {
        struct prestera_msg_cmd cmd;
        __le32 flood_domain_idx;
@@ -725,6 +720,13 @@ struct prestera_msg_flood_domain_port {
        __le16 port_type;
 };
 
+struct prestera_msg_flood_domain_ports_set_req {
+       struct prestera_msg_cmd cmd;
+       __le32 flood_domain_idx;
+       __le32 ports_num;
+       struct prestera_msg_flood_domain_port ports[] __counted_by_le(ports_num);
+};
+
 struct prestera_msg_mdb_create_req {
        struct prestera_msg_cmd cmd;
        __le32 flood_domain_idx;
@@ -1371,23 +1373,18 @@ int prestera_hw_vtcam_rule_add(struct prestera_switch *sw,
                               struct prestera_acl_hw_action_info *act,
                               u8 n_act, u32 *rule_id)
 {
-       struct prestera_msg_acl_action *actions_msg;
        struct prestera_msg_vtcam_rule_add_req *req;
        struct prestera_msg_vtcam_resp resp;
-       void *buff;
-       u32 size;
+       size_t size;
        int err;
        u8 i;
 
-       size = sizeof(*req) + sizeof(*actions_msg) * n_act;
-
-       buff = kzalloc(size, GFP_KERNEL);
-       if (!buff)
+       size = struct_size(req, actions_msg, n_act);
+       req = kzalloc(size, GFP_KERNEL);
+       if (!req)
                return -ENOMEM;
 
-       req = buff;
        req->n_act = __cpu_to_le32(n_act);
-       actions_msg = buff + sizeof(*req);
 
        /* put acl matches into the message */
        memcpy(req->key, key, sizeof(req->key));
@@ -1395,7 +1392,7 @@ int prestera_hw_vtcam_rule_add(struct prestera_switch *sw,
 
        /* put acl actions into the message */
        for (i = 0; i < n_act; i++) {
-               err = prestera_acl_rule_add_put_action(&actions_msg[i],
+               err = prestera_acl_rule_add_put_action(&req->actions_msg[i],
                                                       &act[i]);
                if (err)
                        goto free_buff;
@@ -1411,7 +1408,7 @@ int prestera_hw_vtcam_rule_add(struct prestera_switch *sw,
 
        *rule_id = __le32_to_cpu(resp.rule_id);
 free_buff:
-       kfree(buff);
+       kfree(req);
        return err;
 }
 
@@ -2461,14 +2458,13 @@ int prestera_hw_flood_domain_ports_set(struct prestera_flood_domain *domain)
 {
        struct prestera_flood_domain_port *flood_domain_port;
        struct prestera_msg_flood_domain_ports_set_req *req;
-       struct prestera_msg_flood_domain_port *ports;
        struct prestera_switch *sw = domain->sw;
        struct prestera_port *port;
        u32 ports_num = 0;
-       int buf_size;
-       void *buff;
+       size_t buf_size;
        u16 lag_id;
        int err;
+       int i = 0;
 
        list_for_each_entry(flood_domain_port, &domain->flood_domain_port_list,
                            flood_domain_port_node)
@@ -2477,15 +2473,11 @@ int prestera_hw_flood_domain_ports_set(struct prestera_flood_domain *domain)
        if (!ports_num)
                return -EINVAL;
 
-       buf_size = sizeof(*req) + sizeof(*ports) * ports_num;
-
-       buff = kmalloc(buf_size, GFP_KERNEL);
-       if (!buff)
+       buf_size = struct_size(req, ports, ports_num);
+       req = kmalloc(buf_size, GFP_KERNEL);
+       if (!req)
                return -ENOMEM;
 
-       req = buff;
-       ports = buff + sizeof(*req);
-
        req->flood_domain_idx = __cpu_to_le32(domain->idx);
        req->ports_num = __cpu_to_le32(ports_num);
 
@@ -2494,31 +2486,30 @@ int prestera_hw_flood_domain_ports_set(struct prestera_flood_domain *domain)
                if (netif_is_lag_master(flood_domain_port->dev)) {
                        if (prestera_lag_id(sw, flood_domain_port->dev,
                                            &lag_id)) {
-                               kfree(buff);
+                               kfree(req);
                                return -EINVAL;
                        }
 
-                       ports->port_type =
+                       req->ports[i].port_type =
                                __cpu_to_le16(PRESTERA_HW_FLOOD_DOMAIN_PORT_TYPE_LAG);
-                       ports->lag_id = __cpu_to_le16(lag_id);
+                       req->ports[i].lag_id = __cpu_to_le16(lag_id);
                } else {
                        port = prestera_port_dev_lower_find(flood_domain_port->dev);
 
-                       ports->port_type =
+                       req->ports[i].port_type =
                                __cpu_to_le16(PRESTERA_HW_FDB_ENTRY_TYPE_REG_PORT);
-                       ports->dev_num = __cpu_to_le32(port->dev_id);
-                       ports->port_num = __cpu_to_le32(port->hw_id);
+                       req->ports[i].dev_num = __cpu_to_le32(port->dev_id);
+                       req->ports[i].port_num = __cpu_to_le32(port->hw_id);
                }
 
-               ports->vid = __cpu_to_le16(flood_domain_port->vid);
-
-               ports++;
+               req->ports[i].vid = __cpu_to_le16(flood_domain_port->vid);
+               i++;
        }
 
        err = prestera_cmd(sw, PRESTERA_CMD_TYPE_FLOOD_DOMAIN_PORTS_SET,
                           &req->cmd, buf_size);
 
-       kfree(buff);
+       kfree(req);
 
        return err;
 }