Checks are presently in place in validate_nla() to ensure strings greater than 2 are not passed in by the user which could potentially cause issues. However, there is nothing to prevent userspace from only providing a single (1) Byte as the data length parameter via nla_put(). If this were to happen, it would cause an OOB read in regulatory_hint_user(), since it makes assumptions that alpha2[0] and alpha2[1] will always be accessible. Add an additional check, to ensure enough data has been allocated to hold both Bytes. Cc: <stable@xxxxxxxxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: Paolo Abeni <pabeni@xxxxxxxxxx> Cc: linux-wireless@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> --- net/wireless/nl80211.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index ee1c2b6b69711..80a516033db36 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -7536,6 +7536,10 @@ static int nl80211_req_set_reg(struct sk_buff *skb, struct genl_info *info) if (!info->attrs[NL80211_ATTR_REG_ALPHA2]) return -EINVAL; + if (nla_len(info->attrs[NL80211_ATTR_REG_ALPHA2]) != + nl80211_policy[NL80211_ATTR_REG_ALPHA2].len) + return -EINVAL; + data = nla_data(info->attrs[NL80211_ATTR_REG_ALPHA2]); return regulatory_hint_user(data, user_reg_hint_type); case NL80211_USER_REG_HINT_INDOOR: -- 2.35.1.1094.g7c7d902a7c-goog
