nl80211: Use struct_size() in kzalloc()
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, GFP_KERNEL)
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
Notice that, in this case, variable size_of_regd is not necessary,
hence it is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e7984f0..64f1912 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3876,8 +3876,7 @@ static struct cfg80211_acl_data *parse_acl_data(struct wiphy *wiphy,
if (n_entries > wiphy->max_acl_mac_addrs)
return ERR_PTR(-ENOTSUPP);
- acl = kzalloc(sizeof(*acl) + (sizeof(struct mac_address) * n_entries),
- GFP_KERNEL);
+ acl = kzalloc(struct_size(acl, mac_addrs, n_entries), GFP_KERNEL);
if (!acl)
return ERR_PTR(-ENOMEM);
@@ -6916,7 +6915,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
struct nlattr *nl_reg_rule;
char *alpha2;
int rem_reg_rules, r;
- u32 num_rules = 0, rule_idx = 0, size_of_regd;
+ u32 num_rules = 0, rule_idx = 0;
enum nl80211_dfs_regions dfs_region = NL80211_DFS_UNSET;
struct ieee80211_regdomain *rd;
@@ -6941,10 +6940,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
if (!reg_is_valid_request(alpha2))
return -EINVAL;
- size_of_regd = sizeof(struct ieee80211_regdomain) +
- num_rules * sizeof(struct ieee80211_reg_rule);
-
- rd = kzalloc(size_of_regd, GFP_KERNEL);
+ rd = kzalloc(struct_size(rd, reg_rules, num_rules), GFP_KERNEL);
if (!rd)
return -ENOMEM;
