netdev - [PATCH][next] cfg80211: use struct

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190403182334.GA3986@embeddedor>
Date:   Wed, 3 Apr 2019 13:23:34 -0500
From:   "Gustavo A. R. Silva" <gustavo@...eddedor.com>
To:     Jussi Kivilinna <jussi.kivilinna@....fi>,
        Kalle Valo <kvalo@...eaurora.org>,
        "David S. Miller" <davem@...emloft.net>
Cc:     linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Subject: [PATCH][next] cfg80211: use struct_size() helper

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace code of the following form:

sizeof(*pmkids) + max_pmkids * sizeof(pmkids->bssid_info[0])

with:

struct_size(pmkids, bssid_info, num_pmkids)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@...eddedor.com>
---
 drivers/net/wireless/rndis_wlan.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c
index 51e4e92d95a0..e07a1152cec1 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -1707,7 +1707,7 @@ static struct ndis_80211_pmkid *get_device_pmkids(struct usbnet *usbdev)
 	int len, ret, max_pmkids;
 
 	max_pmkids = priv->wdev.wiphy->max_num_pmkids;
-	len = sizeof(*pmkids) + max_pmkids * sizeof(pmkids->bssid_info[0]);
+	len = struct_size(pmkids, bssid_info, max_pmkids);
 
 	pmkids = kzalloc(len, GFP_KERNEL);
 	if (!pmkids)
@@ -1740,7 +1740,7 @@ static int set_device_pmkids(struct usbnet *usbdev,
 	int ret, len, num_pmkids;
 
 	num_pmkids = le32_to_cpu(pmkids->bssid_info_count);
-	len = sizeof(*pmkids) + num_pmkids * sizeof(pmkids->bssid_info[0]);
+	len = struct_size(pmkids, bssid_info, num_pmkids);
 	pmkids->length = cpu_to_le32(len);
 
 	debug_print_pmkids(usbdev, pmkids, __func__);
@@ -1761,7 +1761,7 @@ static struct ndis_80211_pmkid *remove_pmkid(struct usbnet *usbdev,
 						struct cfg80211_pmksa *pmksa,
 						int max_pmkids)
 {
-	int i, newlen, err;
+	int i, err;
 	unsigned int count;
 
 	count = le32_to_cpu(pmkids->bssid_info_count);
@@ -1786,9 +1786,7 @@ static struct ndis_80211_pmkid *remove_pmkid(struct usbnet *usbdev,
 		pmkids->bssid_info[i] = pmkids->bssid_info[i + 1];
 
 	count--;
-	newlen = sizeof(*pmkids) + count * sizeof(pmkids->bssid_info[0]);
-
-	pmkids->length = cpu_to_le32(newlen);
+	pmkids->length = cpu_to_le32(struct_size(pmkids, bssid_info, count));
 	pmkids->bssid_info_count = cpu_to_le32(count);
 
 	return pmkids;
@@ -1831,7 +1829,7 @@ static struct ndis_80211_pmkid *update_pmkid(struct usbnet *usbdev,
 	}
 
 	/* add new pmkid */
-	newlen = sizeof(*pmkids) + (count + 1) * sizeof(pmkids->bssid_info[0]);
+	newlen = struct_size(pmkids, bssid_info, count + 1);
 
 	new_pmkids = krealloc(pmkids, newlen, GFP_KERNEL);
 	if (!new_pmkids) {
-- 
2.21.0