Messages in this thread Patch in this message | | | From | Lee Jones <> | Subject | [PATCH 1/1] nl80211: Prevent out-of-bounds read when processing NL80211_ATTR_REG_ALPHA2 | Date | Fri, 1 Apr 2022 11:50:46 +0100 |
| |
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@vger.kernel.org> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> --- 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
| |