From 47aa7861b9bf8e8a540f3b11971e4a3f631e8ff4 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 18 Jun 2018 07:41:34 -0500 Subject: [PATCH] mac80211: fix potential null pointer dereference he_op is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after he_op has been properly null checked. Notice that, currently, he_op is already being null checked before calling this function at 4593: 4593 if (!he_oper || 4594 !ieee80211_verify_sta_he_mcs_support(sband, he_oper)) 4595 ifmgd->flags |= IEEE80211_STA_DISABLE_HE; but in case ieee80211_verify_sta_he_mcs_support is ever called without verifying he_oper is not null, we will end up having a null pointer dereference. So, we better don't take any chances. Addresses-Coverity-ID: 1470068 ("Dereference before null check") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 0322d78007ad..f4513031f1bc 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -4458,12 +4458,14 @@ ieee80211_verify_sta_he_mcs_support(struct ieee80211_supported_band *sband, { const struct ieee80211_sta_he_cap *sta_he_cap = ieee80211_get_he_sta_cap(sband); - u16 ap_min_req_set = le16_to_cpu(he_op->he_mcs_nss_set); + u16 ap_min_req_set; int i; if (!sta_he_cap || !he_op) return false; + ap_min_req_set = le16_to_cpu(he_op->he_mcs_nss_set); + /* Need to go over for 80MHz, 160MHz and for 80+80 */ for (i = 0; i < 3; i++) { const struct ieee80211_he_mcs_nss_supp *sta_mcs_nss_supp = -- 2.30.2