nl80211: validate some input better
This patch changes nl80211 to:
* validate that any IE input is a valid IE (stream)
* move some validation code before locking
* require that a reason code is given for both deauth/disassoc
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2456e4e..2f449dd 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -118,6 +118,36 @@
[NL80211_ATTR_REASON_CODE] = { .type = NLA_U16 },
};
+/* IE validation */
+static bool is_valid_ie_attr(const struct nlattr *attr)
+{
+ const u8 *pos;
+ int len;
+
+ if (!attr)
+ return true;
+
+ pos = nla_data(attr);
+ len = nla_len(attr);
+
+ while (len) {
+ u8 elemlen;
+
+ if (len < 2)
+ return false;
+ len -= 2;
+
+ elemlen = pos[1];
+ if (elemlen > len)
+ return false;
+
+ len -= elemlen;
+ pos += 2 + elemlen;
+ }
+
+ return true;
+}
+
/* message building helper */
static inline void *nl80211hdr_put(struct sk_buff *skb, u32 pid, u32 seq,
int flags, u8 cmd)
@@ -1069,6 +1099,9 @@
struct beacon_parameters params;
int haveinfo = 0;
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_BEACON_TAIL]))
+ return -EINVAL;
+
rtnl_lock();
err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -2442,6 +2475,9 @@
enum ieee80211_band band;
size_t ie_len;
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
+ return -EINVAL;
+
rtnl_lock();
err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -2710,6 +2746,12 @@
struct wiphy *wiphy;
int err;
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
+ return -EINVAL;
+
+ if (!info->attrs[NL80211_ATTR_MAC])
+ return -EINVAL;
+
rtnl_lock();
err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -2731,11 +2773,6 @@
goto out;
}
- if (!info->attrs[NL80211_ATTR_MAC]) {
- err = -EINVAL;
- goto out;
- }
-
wiphy = &drv->wiphy;
memset(&req, 0, sizeof(req));
@@ -2788,6 +2825,13 @@
struct wiphy *wiphy;
int err;
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
+ return -EINVAL;
+
+ if (!info->attrs[NL80211_ATTR_MAC] ||
+ !info->attrs[NL80211_ATTR_SSID])
+ return -EINVAL;
+
rtnl_lock();
err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -2809,12 +2853,6 @@
goto out;
}
- if (!info->attrs[NL80211_ATTR_MAC] ||
- !info->attrs[NL80211_ATTR_SSID]) {
- err = -EINVAL;
- goto out;
- }
-
wiphy = &drv->wiphy;
memset(&req, 0, sizeof(req));
@@ -2856,6 +2894,15 @@
struct wiphy *wiphy;
int err;
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
+ return -EINVAL;
+
+ if (!info->attrs[NL80211_ATTR_MAC])
+ return -EINVAL;
+
+ if (!info->attrs[NL80211_ATTR_REASON_CODE])
+ return -EINVAL;
+
rtnl_lock();
err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -2877,24 +2924,16 @@
goto out;
}
- if (!info->attrs[NL80211_ATTR_MAC]) {
- err = -EINVAL;
- goto out;
- }
-
wiphy = &drv->wiphy;
memset(&req, 0, sizeof(req));
req.peer_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
- if (info->attrs[NL80211_ATTR_REASON_CODE]) {
- req.reason_code =
- nla_get_u16(info->attrs[NL80211_ATTR_REASON_CODE]);
- if (req.reason_code == 0) {
- /* Reason Code 0 is reserved */
- err = -EINVAL;
- goto out;
- }
+ req.reason_code = nla_get_u16(info->attrs[NL80211_ATTR_REASON_CODE]);
+ if (req.reason_code == 0) {
+ /* Reason Code 0 is reserved */
+ err = -EINVAL;
+ goto out;
}
if (info->attrs[NL80211_ATTR_IE]) {
@@ -2920,6 +2959,15 @@
struct wiphy *wiphy;
int err;
+ if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_IE]))
+ return -EINVAL;
+
+ if (!info->attrs[NL80211_ATTR_MAC])
+ return -EINVAL;
+
+ if (!info->attrs[NL80211_ATTR_REASON_CODE])
+ return -EINVAL;
+
rtnl_lock();
err = get_drv_dev_by_info_ifindex(info->attrs, &drv, &dev);
@@ -2941,24 +2989,16 @@
goto out;
}
- if (!info->attrs[NL80211_ATTR_MAC]) {
- err = -EINVAL;
- goto out;
- }
-
wiphy = &drv->wiphy;
memset(&req, 0, sizeof(req));
req.peer_addr = nla_data(info->attrs[NL80211_ATTR_MAC]);
- if (info->attrs[NL80211_ATTR_REASON_CODE]) {
- req.reason_code =
- nla_get_u16(info->attrs[NL80211_ATTR_REASON_CODE]);
- if (req.reason_code == 0) {
- /* Reason Code 0 is reserved */
- err = -EINVAL;
- goto out;
- }
+ req.reason_code = nla_get_u16(info->attrs[NL80211_ATTR_REASON_CODE]);
+ if (req.reason_code == 0) {
+ /* Reason Code 0 is reserved */
+ err = -EINVAL;
+ goto out;
}
if (info->attrs[NL80211_ATTR_IE]) {