Some structures contain flexible arrays at the end and the counter for
them, but the counter has explicit Endianness and thus __counted_by()
can't be used directly.
To increase test coverage for potential problems without breaking
anything, introduce __counted_by_{le,be} defined depending on platform's
Endianness to either __counted_by() when applicable or noop otherwise.
The first user will be virtchnl2.h from idpf just as example with 9 flex
structures having Little Endian counters.
Maybe it would be a good idea to introduce such attributes on compiler
level if possible, but for now let's stop on what we have.
Alexander Lobakin (3):
compiler_types: add Endianness-dependent __counted_by_{le,be}
idpf: make virtchnl2.h self-contained
idpf: sprinkle __counted_by{,_le}() in the virtchnl2 header
Documentation/conf.py | 2 ++
scripts/kernel-doc | 1 +
include/linux/compiler_types.h | 11 ++++++++++
drivers/net/ethernet/intel/idpf/virtchnl2.h | 24 ++++++++++-----------
4 files changed, 26 insertions(+), 12 deletions(-)
---
From RFC[0]:
* teach kdoc new attributes (Simon, Kees);
* add Acked-by (Kees);
* fix a couple typos;
* send to net-next (Kees).
[0] https://lore.kernel.org/netdev/[email protected]
--
2.44.0
Both virtchnl2.h and its consumer idpf_virtchnl.c are very error-prone.
There are 10 structures with flexible arrays at the end, but 9 of them
has flex member counter in Little Endian.
Make the code a bit more robust by applying __counted_by_le() to those
9. LE platforms is the main target for this driver, so they would
receive additional protection.
While we're here, add __counted_by() to virtchnl2_ptype::proto_id, as
its counter is `u8` regardless of the Endianness.
Compile test on x86_64 (LE) didn't reveal any new issues after applying
the attributes.
Acked-by: Kees Cook <[email protected]>
Signed-off-by: Alexander Lobakin <[email protected]>
---
drivers/net/ethernet/intel/idpf/virtchnl2.h | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h
index 29419211b3d9..63deb120359c 100644
--- a/drivers/net/ethernet/intel/idpf/virtchnl2.h
+++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h
@@ -555,7 +555,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_queue_reg_chunk);
struct virtchnl2_queue_reg_chunks {
__le16 num_chunks;
u8 pad[6];
- struct virtchnl2_queue_reg_chunk chunks[];
+ struct virtchnl2_queue_reg_chunk chunks[] __counted_by_le(num_chunks);
};
VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_reg_chunks);
@@ -703,7 +703,7 @@ struct virtchnl2_config_tx_queues {
__le32 vport_id;
__le16 num_qinfo;
u8 pad[10];
- struct virtchnl2_txq_info qinfo[];
+ struct virtchnl2_txq_info qinfo[] __counted_by_le(num_qinfo);
};
VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_config_tx_queues);
@@ -782,7 +782,7 @@ struct virtchnl2_config_rx_queues {
__le32 vport_id;
__le16 num_qinfo;
u8 pad[18];
- struct virtchnl2_rxq_info qinfo[];
+ struct virtchnl2_rxq_info qinfo[] __counted_by_le(num_qinfo);
};
VIRTCHNL2_CHECK_STRUCT_LEN(24, virtchnl2_config_rx_queues);
@@ -868,7 +868,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_vector_chunk);
struct virtchnl2_vector_chunks {
__le16 num_vchunks;
u8 pad[14];
- struct virtchnl2_vector_chunk vchunks[];
+ struct virtchnl2_vector_chunk vchunks[] __counted_by_le(num_vchunks);
};
VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_vector_chunks);
@@ -912,7 +912,7 @@ struct virtchnl2_rss_lut {
__le16 lut_entries_start;
__le16 lut_entries;
u8 pad[4];
- __le32 lut[];
+ __le32 lut[] __counted_by_le(lut_entries);
};
VIRTCHNL2_CHECK_STRUCT_LEN(12, virtchnl2_rss_lut);
@@ -977,7 +977,7 @@ struct virtchnl2_ptype {
u8 ptype_id_8;
u8 proto_id_count;
__le16 pad;
- __le16 proto_id[];
+ __le16 proto_id[] __counted_by(proto_id_count);
} __packed __aligned(2);
VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype);
@@ -1104,7 +1104,7 @@ struct virtchnl2_rss_key {
__le32 vport_id;
__le16 key_len;
u8 pad;
- u8 key_flex[];
+ u8 key_flex[] __counted_by_le(key_len);
} __packed;
VIRTCHNL2_CHECK_STRUCT_LEN(7, virtchnl2_rss_key);
@@ -1131,7 +1131,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_chunk);
struct virtchnl2_queue_chunks {
__le16 num_chunks;
u8 pad[6];
- struct virtchnl2_queue_chunk chunks[];
+ struct virtchnl2_queue_chunk chunks[] __counted_by_le(num_chunks);
};
VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_chunks);
@@ -1195,7 +1195,7 @@ struct virtchnl2_queue_vector_maps {
__le32 vport_id;
__le16 num_qv_maps;
u8 pad[10];
- struct virtchnl2_queue_vector qv_maps[];
+ struct virtchnl2_queue_vector qv_maps[] __counted_by_le(num_qv_maps);
};
VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_vector_maps);
@@ -1247,7 +1247,7 @@ struct virtchnl2_mac_addr_list {
__le32 vport_id;
__le16 num_mac_addr;
u8 pad[2];
- struct virtchnl2_mac_addr mac_addr_list[];
+ struct virtchnl2_mac_addr mac_addr_list[] __counted_by_le(num_mac_addr);
};
VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_mac_addr_list);
--
2.44.0
On 3/26/24 10:41, Alexander Lobakin wrote:
> Both virtchnl2.h and its consumer idpf_virtchnl.c are very error-prone.
> There are 10 structures with flexible arrays at the end, but 9 of them
> has flex member counter in Little Endian.
> Make the code a bit more robust by applying __counted_by_le() to those
> 9. LE platforms is the main target for this driver, so they would
> receive additional protection.
> While we're here, add __counted_by() to virtchnl2_ptype::proto_id, as
> its counter is `u8` regardless of the Endianness.
> Compile test on x86_64 (LE) didn't reveal any new issues after applying
> the attributes.
>
> Acked-by: Kees Cook <[email protected]>
> Signed-off-by: Alexander Lobakin <[email protected]>
LGTM:
Acked-by: Gustavo A. R. Silva <[email protected]>
Thanks
--
Gustavo
> ---
> drivers/net/ethernet/intel/idpf/virtchnl2.h | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/idpf/virtchnl2.h b/drivers/net/ethernet/intel/idpf/virtchnl2.h
> index 29419211b3d9..63deb120359c 100644
> --- a/drivers/net/ethernet/intel/idpf/virtchnl2.h
> +++ b/drivers/net/ethernet/intel/idpf/virtchnl2.h
> @@ -555,7 +555,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_queue_reg_chunk);
> struct virtchnl2_queue_reg_chunks {
> __le16 num_chunks;
> u8 pad[6];
> - struct virtchnl2_queue_reg_chunk chunks[];
> + struct virtchnl2_queue_reg_chunk chunks[] __counted_by_le(num_chunks);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_reg_chunks);
>
> @@ -703,7 +703,7 @@ struct virtchnl2_config_tx_queues {
> __le32 vport_id;
> __le16 num_qinfo;
> u8 pad[10];
> - struct virtchnl2_txq_info qinfo[];
> + struct virtchnl2_txq_info qinfo[] __counted_by_le(num_qinfo);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_config_tx_queues);
>
> @@ -782,7 +782,7 @@ struct virtchnl2_config_rx_queues {
> __le32 vport_id;
> __le16 num_qinfo;
> u8 pad[18];
> - struct virtchnl2_rxq_info qinfo[];
> + struct virtchnl2_rxq_info qinfo[] __counted_by_le(num_qinfo);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(24, virtchnl2_config_rx_queues);
>
> @@ -868,7 +868,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(32, virtchnl2_vector_chunk);
> struct virtchnl2_vector_chunks {
> __le16 num_vchunks;
> u8 pad[14];
> - struct virtchnl2_vector_chunk vchunks[];
> + struct virtchnl2_vector_chunk vchunks[] __counted_by_le(num_vchunks);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_vector_chunks);
>
> @@ -912,7 +912,7 @@ struct virtchnl2_rss_lut {
> __le16 lut_entries_start;
> __le16 lut_entries;
> u8 pad[4];
> - __le32 lut[];
> + __le32 lut[] __counted_by_le(lut_entries);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(12, virtchnl2_rss_lut);
>
> @@ -977,7 +977,7 @@ struct virtchnl2_ptype {
> u8 ptype_id_8;
> u8 proto_id_count;
> __le16 pad;
> - __le16 proto_id[];
> + __le16 proto_id[] __counted_by(proto_id_count);
> } __packed __aligned(2);
> VIRTCHNL2_CHECK_STRUCT_LEN(6, virtchnl2_ptype);
>
> @@ -1104,7 +1104,7 @@ struct virtchnl2_rss_key {
> __le32 vport_id;
> __le16 key_len;
> u8 pad;
> - u8 key_flex[];
> + u8 key_flex[] __counted_by_le(key_len);
> } __packed;
> VIRTCHNL2_CHECK_STRUCT_LEN(7, virtchnl2_rss_key);
>
> @@ -1131,7 +1131,7 @@ VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_chunk);
> struct virtchnl2_queue_chunks {
> __le16 num_chunks;
> u8 pad[6];
> - struct virtchnl2_queue_chunk chunks[];
> + struct virtchnl2_queue_chunk chunks[] __counted_by_le(num_chunks);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_queue_chunks);
>
> @@ -1195,7 +1195,7 @@ struct virtchnl2_queue_vector_maps {
> __le32 vport_id;
> __le16 num_qv_maps;
> u8 pad[10];
> - struct virtchnl2_queue_vector qv_maps[];
> + struct virtchnl2_queue_vector qv_maps[] __counted_by_le(num_qv_maps);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(16, virtchnl2_queue_vector_maps);
>
> @@ -1247,7 +1247,7 @@ struct virtchnl2_mac_addr_list {
> __le32 vport_id;
> __le16 num_mac_addr;
> u8 pad[2];
> - struct virtchnl2_mac_addr mac_addr_list[];
> + struct virtchnl2_mac_addr mac_addr_list[] __counted_by_le(num_mac_addr);
> };
> VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_mac_addr_list);
>