[PATCH net-next 2/3] virtchnl: fix fake 1-elem arrays in structures allocated as `nents + 1`

From: Alexander Lobakin
Date: Fri Jul 28 2023 - 11:53:50 EST


There are five virtchnl structures, which are allocated and checked in
the code as `nents + 1`, meaning that they always have memory for one
excessive element regardless of their actual number. This comes from
that their sizeof() includes space for 1 element and then they get
allocated via struct_size() or its open-coded equivalents, passing
the actual number of elements.
Expand virtchnl_struct_size() to handle such structures and replace
those 1-elem arrays with proper flex ones. Also fix several places
which open-code %IAVF_VIRTCHNL_VF_RESOURCE_SIZE. Finally, let the
virtchnl_ether_addr_list size be computed automatically when there's
no enough space for the whole list, otherwise we have to open-code
reverse struct_size() logics.

Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
---
.../ethernet/intel/i40e/i40e_virtchnl_pf.c | 2 +-
drivers/net/ethernet/intel/iavf/iavf.h | 6 +-
.../net/ethernet/intel/iavf/iavf_virtchnl.c | 44 +++++++-------
drivers/net/ethernet/intel/ice/ice_virtchnl.c | 2 +-
include/linux/avf/virtchnl.h | 57 ++++++++++++-------
5 files changed, 59 insertions(+), 52 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 398fb4854cbe..030738409f76 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -2103,7 +2103,7 @@ static int i40e_vc_get_vf_resources_msg(struct i40e_vf *vf, u8 *msg)
goto err;
}

- len = struct_size(vfres, vsi_res, num_vsis);
+ len = virtchnl_struct_size(vfres, vsi_res, num_vsis);
vfres = kzalloc(len, GFP_KERNEL);
if (!vfres) {
aq_ret = I40E_ERR_NO_MEMORY;
diff --git a/drivers/net/ethernet/intel/iavf/iavf.h b/drivers/net/ethernet/intel/iavf/iavf.h
index 8cbdebc5b698..85fba85fbb23 100644
--- a/drivers/net/ethernet/intel/iavf/iavf.h
+++ b/drivers/net/ethernet/intel/iavf/iavf.h
@@ -92,9 +92,9 @@ struct iavf_vsi {
#define IAVF_MBPS_DIVISOR 125000 /* divisor to convert to Mbps */
#define IAVF_MBPS_QUANTA 50

-#define IAVF_VIRTCHNL_VF_RESOURCE_SIZE (sizeof(struct virtchnl_vf_resource) + \
- (IAVF_MAX_VF_VSI * \
- sizeof(struct virtchnl_vsi_resource)))
+#define IAVF_VIRTCHNL_VF_RESOURCE_SIZE \
+ virtchnl_struct_size((struct virtchnl_vf_resource *)NULL, \
+ vsi_res, IAVF_MAX_VF_VSI)

/* MAX_MSIX_Q_VECTORS of these are allocated,
* but we only use one per queue-specific vector.
diff --git a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
index 10f03054a603..4fdac698eb38 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
@@ -215,8 +215,7 @@ int iavf_get_vf_config(struct iavf_adapter *adapter)
u16 len;
int err;

- len = sizeof(struct virtchnl_vf_resource) +
- IAVF_MAX_VF_VSI * sizeof(struct virtchnl_vsi_resource);
+ len = IAVF_VIRTCHNL_VF_RESOURCE_SIZE;
event.buf_len = len;
event.msg_buf = kzalloc(len, GFP_KERNEL);
if (!event.msg_buf)
@@ -284,7 +283,7 @@ void iavf_configure_queues(struct iavf_adapter *adapter)
return;
}
adapter->current_op = VIRTCHNL_OP_CONFIG_VSI_QUEUES;
- len = struct_size(vqci, qpair, pairs);
+ len = virtchnl_struct_size(vqci, qpair, pairs);
vqci = kzalloc(len, GFP_KERNEL);
if (!vqci)
return;
@@ -397,7 +396,7 @@ void iavf_map_queues(struct iavf_adapter *adapter)

q_vectors = adapter->num_msix_vectors - NONQ_VECS;

- len = struct_size(vimi, vecmap, adapter->num_msix_vectors);
+ len = virtchnl_struct_size(vimi, vecmap, adapter->num_msix_vectors);
vimi = kzalloc(len, GFP_KERNEL);
if (!vimi)
return;
@@ -476,13 +475,11 @@ void iavf_add_ether_addrs(struct iavf_adapter *adapter)
}
adapter->current_op = VIRTCHNL_OP_ADD_ETH_ADDR;

- len = struct_size(veal, list, count);
+ len = virtchnl_struct_size(veal, list, count);
if (len > IAVF_MAX_AQ_BUF_SIZE) {
dev_warn(&adapter->pdev->dev, "Too many add MAC changes in one request\n");
- count = (IAVF_MAX_AQ_BUF_SIZE -
- sizeof(struct virtchnl_ether_addr_list)) /
- sizeof(struct virtchnl_ether_addr);
- len = struct_size(veal, list, count);
+ while (len > IAVF_MAX_AQ_BUF_SIZE)
+ len = virtchnl_struct_size(veal, list, --count);
more = true;
}

@@ -547,13 +544,11 @@ void iavf_del_ether_addrs(struct iavf_adapter *adapter)
}
adapter->current_op = VIRTCHNL_OP_DEL_ETH_ADDR;

- len = struct_size(veal, list, count);
+ len = virtchnl_struct_size(veal, list, count);
if (len > IAVF_MAX_AQ_BUF_SIZE) {
dev_warn(&adapter->pdev->dev, "Too many delete MAC changes in one request\n");
- count = (IAVF_MAX_AQ_BUF_SIZE -
- sizeof(struct virtchnl_ether_addr_list)) /
- sizeof(struct virtchnl_ether_addr);
- len = struct_size(veal, list, count);
+ while (len > IAVF_MAX_AQ_BUF_SIZE)
+ len = virtchnl_struct_size(veal, list, --count);
more = true;
}
veal = kzalloc(len, GFP_ATOMIC);
@@ -687,12 +682,12 @@ void iavf_add_vlans(struct iavf_adapter *adapter)

adapter->current_op = VIRTCHNL_OP_ADD_VLAN;

- len = sizeof(*vvfl) + (count * sizeof(u16));
+ len = virtchnl_struct_size(vvfl, vlan_id, count);
if (len > IAVF_MAX_AQ_BUF_SIZE) {
dev_warn(&adapter->pdev->dev, "Too many add VLAN changes in one request\n");
- count = (IAVF_MAX_AQ_BUF_SIZE - sizeof(*vvfl)) /
- sizeof(u16);
- len = sizeof(*vvfl) + (count * sizeof(u16));
+ while (len > IAVF_MAX_AQ_BUF_SIZE)
+ len = virtchnl_struct_size(vvfl, vlan_id,
+ --count);
more = true;
}
vvfl = kzalloc(len, GFP_ATOMIC);
@@ -838,12 +833,12 @@ void iavf_del_vlans(struct iavf_adapter *adapter)

adapter->current_op = VIRTCHNL_OP_DEL_VLAN;

- len = sizeof(*vvfl) + (count * sizeof(u16));
+ len = virtchnl_struct_size(vvfl, vlan_id, count);
if (len > IAVF_MAX_AQ_BUF_SIZE) {
dev_warn(&adapter->pdev->dev, "Too many delete VLAN changes in one request\n");
- count = (IAVF_MAX_AQ_BUF_SIZE - sizeof(*vvfl)) /
- sizeof(u16);
- len = sizeof(*vvfl) + (count * sizeof(u16));
+ while (len > IAVF_MAX_AQ_BUF_SIZE)
+ len = virtchnl_struct_size(vvfl, vlan_id,
+ --count);
more = true;
}
vvfl = kzalloc(len, GFP_ATOMIC);
@@ -2173,9 +2168,8 @@ void iavf_virtchnl_completion(struct iavf_adapter *adapter,
}
break;
case VIRTCHNL_OP_GET_VF_RESOURCES: {
- u16 len = sizeof(struct virtchnl_vf_resource) +
- IAVF_MAX_VF_VSI *
- sizeof(struct virtchnl_vsi_resource);
+ u16 len = IAVF_VIRTCHNL_VF_RESOURCE_SIZE;
+
memcpy(adapter->vf_res, msg, min(msglen, len));
iavf_validate_num_queues(adapter);
iavf_vf_parse_hw_config(&adapter->hw, adapter->vf_res);
diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl.c b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
index 625da88e7965..a5a82833cdc6 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl.c
@@ -428,7 +428,7 @@ static int ice_vc_get_vf_res_msg(struct ice_vf *vf, u8 *msg)
goto err;
}

- len = sizeof(struct virtchnl_vf_resource);
+ len = virtchnl_struct_size(vfres, vsi_res, 0);

vfres = kzalloc(len, GFP_KERNEL);
if (!vfres) {
diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h
index 3ab207c14809..c1a20b533fc0 100644
--- a/include/linux/avf/virtchnl.h
+++ b/include/linux/avf/virtchnl.h
@@ -268,10 +268,11 @@ struct virtchnl_vf_resource {
u32 rss_key_size;
u32 rss_lut_size;

- struct virtchnl_vsi_resource vsi_res[1];
+ struct virtchnl_vsi_resource vsi_res[];
};

-VIRTCHNL_CHECK_STRUCT_LEN(36, virtchnl_vf_resource);
+VIRTCHNL_CHECK_STRUCT_LEN(20, virtchnl_vf_resource);
+#define virtchnl_vf_resource_LEGACY_SIZEOF 36

/* VIRTCHNL_OP_CONFIG_TX_QUEUE
* VF sends this message to set up parameters for one TX queue.
@@ -340,10 +341,11 @@ struct virtchnl_vsi_queue_config_info {
u16 vsi_id;
u16 num_queue_pairs;
u32 pad;
- struct virtchnl_queue_pair_info qpair[1];
+ struct virtchnl_queue_pair_info qpair[];
};

-VIRTCHNL_CHECK_STRUCT_LEN(72, virtchnl_vsi_queue_config_info);
+VIRTCHNL_CHECK_STRUCT_LEN(8, virtchnl_vsi_queue_config_info);
+#define virtchnl_vsi_queue_config_info_LEGACY_SIZEOF 72

/* VIRTCHNL_OP_REQUEST_QUEUES
* VF sends this message to request the PF to allocate additional queues to
@@ -385,10 +387,11 @@ VIRTCHNL_CHECK_STRUCT_LEN(12, virtchnl_vector_map);

struct virtchnl_irq_map_info {
u16 num_vectors;
- struct virtchnl_vector_map vecmap[1];
+ struct virtchnl_vector_map vecmap[];
};

-VIRTCHNL_CHECK_STRUCT_LEN(14, virtchnl_irq_map_info);
+VIRTCHNL_CHECK_STRUCT_LEN(2, virtchnl_irq_map_info);
+#define virtchnl_irq_map_info_LEGACY_SIZEOF 14

/* VIRTCHNL_OP_ENABLE_QUEUES
* VIRTCHNL_OP_DISABLE_QUEUES
@@ -459,10 +462,11 @@ VIRTCHNL_CHECK_STRUCT_LEN(8, virtchnl_ether_addr);
struct virtchnl_ether_addr_list {
u16 vsi_id;
u16 num_elements;
- struct virtchnl_ether_addr list[1];
+ struct virtchnl_ether_addr list[];
};

-VIRTCHNL_CHECK_STRUCT_LEN(12, virtchnl_ether_addr_list);
+VIRTCHNL_CHECK_STRUCT_LEN(4, virtchnl_ether_addr_list);
+#define virtchnl_ether_addr_list_LEGACY_SIZEOF 12

/* VIRTCHNL_OP_ADD_VLAN
* VF sends this message to add one or more VLAN tag filters for receives.
@@ -481,10 +485,11 @@ VIRTCHNL_CHECK_STRUCT_LEN(12, virtchnl_ether_addr_list);
struct virtchnl_vlan_filter_list {
u16 vsi_id;
u16 num_elements;
- u16 vlan_id[1];
+ u16 vlan_id[];
};

-VIRTCHNL_CHECK_STRUCT_LEN(6, virtchnl_vlan_filter_list);
+VIRTCHNL_CHECK_STRUCT_LEN(4, virtchnl_vlan_filter_list);
+#define virtchnl_vlan_filter_list_LEGACY_SIZEOF 6

/* This enum is used for all of the VIRTCHNL_VF_OFFLOAD_VLAN_V2_CAPS related
* structures and opcodes.
@@ -1372,11 +1377,19 @@ VIRTCHNL_CHECK_STRUCT_LEN(12, virtchnl_fdir_del);
#define __vss_byone(p, member, count, old) \
(struct_size(p, member, count) + (old - 1 - struct_size(p, member, 0)))

+#define __vss_full(p, member, count, old) \
+ (struct_size(p, member, count) + (old - struct_size(p, member, 0)))
+
#define __vss(type, func, p, member, count) \
struct type: func(p, member, count, type##_LEGACY_SIZEOF)

#define virtchnl_struct_size(p, m, c) \
_Generic(*p, \
+ __vss(virtchnl_vf_resource, __vss_full, p, m, c), \
+ __vss(virtchnl_vsi_queue_config_info, __vss_full, p, m, c), \
+ __vss(virtchnl_irq_map_info, __vss_full, p, m, c), \
+ __vss(virtchnl_ether_addr_list, __vss_full, p, m, c), \
+ __vss(virtchnl_vlan_filter_list, __vss_full, p, m, c), \
__vss(virtchnl_rss_key, __vss_byone, p, m, c), \
__vss(virtchnl_rss_lut, __vss_byone, p, m, c))

@@ -1414,24 +1427,23 @@ virtchnl_vc_validate_vf_msg(struct virtchnl_version_info *ver, u32 v_opcode,
valid_len = sizeof(struct virtchnl_rxq_info);
break;
case VIRTCHNL_OP_CONFIG_VSI_QUEUES:
- valid_len = sizeof(struct virtchnl_vsi_queue_config_info);
+ valid_len = virtchnl_vsi_queue_config_info_LEGACY_SIZEOF;
if (msglen >= valid_len) {
struct virtchnl_vsi_queue_config_info *vqc =
(struct virtchnl_vsi_queue_config_info *)msg;
- valid_len += (vqc->num_queue_pairs *
- sizeof(struct
- virtchnl_queue_pair_info));
+ valid_len = virtchnl_struct_size(vqc, qpair,
+ vqc->num_queue_pairs);
if (vqc->num_queue_pairs == 0)
err_msg_format = true;
}
break;
case VIRTCHNL_OP_CONFIG_IRQ_MAP:
- valid_len = sizeof(struct virtchnl_irq_map_info);
+ valid_len = virtchnl_irq_map_info_LEGACY_SIZEOF;
if (msglen >= valid_len) {
struct virtchnl_irq_map_info *vimi =
(struct virtchnl_irq_map_info *)msg;
- valid_len += (vimi->num_vectors *
- sizeof(struct virtchnl_vector_map));
+ valid_len = virtchnl_struct_size(vimi, vecmap,
+ vimi->num_vectors);
if (vimi->num_vectors == 0)
err_msg_format = true;
}
@@ -1442,23 +1454,24 @@ virtchnl_vc_validate_vf_msg(struct virtchnl_version_info *ver, u32 v_opcode,
break;
case VIRTCHNL_OP_ADD_ETH_ADDR:
case VIRTCHNL_OP_DEL_ETH_ADDR:
- valid_len = sizeof(struct virtchnl_ether_addr_list);
+ valid_len = virtchnl_ether_addr_list_LEGACY_SIZEOF;
if (msglen >= valid_len) {
struct virtchnl_ether_addr_list *veal =
(struct virtchnl_ether_addr_list *)msg;
- valid_len += veal->num_elements *
- sizeof(struct virtchnl_ether_addr);
+ valid_len = virtchnl_struct_size(veal, list,
+ veal->num_elements);
if (veal->num_elements == 0)
err_msg_format = true;
}
break;
case VIRTCHNL_OP_ADD_VLAN:
case VIRTCHNL_OP_DEL_VLAN:
- valid_len = sizeof(struct virtchnl_vlan_filter_list);
+ valid_len = virtchnl_vlan_filter_list_LEGACY_SIZEOF;
if (msglen >= valid_len) {
struct virtchnl_vlan_filter_list *vfl =
(struct virtchnl_vlan_filter_list *)msg;
- valid_len += vfl->num_elements * sizeof(u16);
+ valid_len = virtchnl_struct_size(vfl, vlan_id,
+ vfl->num_elements);
if (vfl->num_elements == 0)
err_msg_format = true;
}
--
2.41.0