nl80211: Use struct_size() in kzalloc() (391d132c) · Commits · 戴 / test

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>

net/wireless/nl80211.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -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;

Admin message