nl80211_set_rekey_data() does not check if the required attributes NL80211_REKEY_DATA_{REPLAY_CTR,KEK,KCK} are present when processing NL80211_CMD_SET_REKEY_OFFLOAD request. This request can be issued by users with CAP_NET_ADMIN privilege and may result in NULL dereference and a system crash. Add a check for the required attributes presence. This patch is based on the patch by bo Zhang.
This fixes CVE-2017-12153. References: https://bugzilla.redhat.com/show_bug.cgi?id=1491046 Fixes: e5497d766ad ("cfg80211/nl80211: support GTK rekey offload") Cc: <sta...@vger.kernel.org> # v3.1-rc1 Reported-by: bo Zhang <zhangbo5891...@gmail.com> Signed-off-by: Vladis Dronov <vdro...@redhat.com> --- net/wireless/nl80211.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 0df8023..fbd5593 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -10903,6 +10903,9 @@ static int nl80211_set_rekey_data(struct sk_buff *skb, struct genl_info *info) if (err) return err; + if (!tb[NL80211_REKEY_DATA_REPLAY_CTR] || !tb[NL80211_REKEY_DATA_KEK] || + !tb[NL80211_REKEY_DATA_KCK]) + return -EINVAL; if (nla_len(tb[NL80211_REKEY_DATA_REPLAY_CTR]) != NL80211_REPLAY_CTR_LEN) return -ERANGE; if (nla_len(tb[NL80211_REKEY_DATA_KEK]) != NL80211_KEK_LEN) -- 2.9.5