diff options
| -rw-r--r-- | net/wireless/nl80211.c | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index d21b1581a665..7386421e2ad3 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -201,6 +201,38 @@ cfg80211_get_dev_from_info(struct net *netns, struct genl_info *info) return __cfg80211_rdev_from_attrs(netns, info->attrs); } +static int validate_beacon_head(const struct nlattr *attr, + struct netlink_ext_ack *extack) +{ + const u8 *data = nla_data(attr); + unsigned int len = nla_len(attr); + const struct element *elem; + const struct ieee80211_mgmt *mgmt = (void *)data; + unsigned int fixedlen = offsetof(struct ieee80211_mgmt, + u.beacon.variable); + + if (len < fixedlen) + goto err; + + if (ieee80211_hdrlen(mgmt->frame_control) != + offsetof(struct ieee80211_mgmt, u.beacon)) + goto err; + + data += fixedlen; + len -= fixedlen; + + for_each_element(elem, data, len) { + /* nothing */ + } + + if (for_each_element_completed(elem, data, len)) + return 0; + +err: + NL_SET_ERR_MSG_ATTR(extack, attr, "malformed beacon head"); + return -EINVAL; +} + static int validate_ie_attr(const struct nlattr *attr, struct netlink_ext_ack *extack) { @@ -338,8 +370,9 @@ const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = { [NL80211_ATTR_BEACON_INTERVAL] = { .type = NLA_U32 }, [NL80211_ATTR_DTIM_PERIOD] = { .type = NLA_U32 }, - [NL80211_ATTR_BEACON_HEAD] = { .type = NLA_BINARY, - .len = IEEE80211_MAX_DATA_LEN }, + [NL80211_ATTR_BEACON_HEAD] = + NLA_POLICY_VALIDATE_FN(NLA_BINARY, validate_beacon_head, + IEEE80211_MAX_DATA_LEN), [NL80211_ATTR_BEACON_TAIL] = NLA_POLICY_VALIDATE_FN(NLA_BINARY, validate_ie_attr, IEEE80211_MAX_DATA_LEN), |