* [PATCH][next] virtchnl: Replace one-element array in struct virtchnl_ether_addr_list
@ 2021-05-25 23:12 Gustavo A. R. Silva
0 siblings, 0 replies; only message in thread
From: Gustavo A. R. Silva @ 2021-05-25 23:12 UTC (permalink / raw)
To: Jesse Brandeburg, Tony Nguyen
Cc: intel-wired-lan, linux-kernel, Gustavo A. R. Silva, linux-hardening
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Refactor the code according to the use of a flexible-array member in struct
virtchnl_ether_addr_list instead of one-element array, and use the
flex_array_size() helper.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
include/linux/avf/virtchnl.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h
index 7ded2b454122..c2e7ffc8ada7 100644
--- a/include/linux/avf/virtchnl.h
+++ b/include/linux/avf/virtchnl.h
@@ -422,10 +422,10 @@ 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);
/* VIRTCHNL_OP_ADD_VLAN
* VF sends this message to add one or more VLAN tag filters for receives.
@@ -1024,8 +1024,8 @@ virtchnl_vc_validate_vf_msg(struct virtchnl_version_info *ver, u32 v_opcode,
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 += flex_array_size(veal, list,
+ veal->num_elements);
if (veal->num_elements == 0)
err_msg_format = true;
}
--
2.27.0
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