mac80211: fix possible NULL pointerderef in obss pd code

he_spr_ie_elem is dereferenced before the NULL check. fix this by moving
the assignment after the check.

fixes commit 697f6c507c74 ("mac80211: propagate HE operation info into
bss_conf")

This was reported by the static code checker.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John Crispin <john@phrozen.org>
Link: https://lore.kernel.org/r/20190813070712.25509-1-john@phrozen.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/he.c b/net/mac80211/he.c
index a02abfc424aa17dac3d9d577ce9a87411339fb2b..736da0035135a863e673cf80a7bc9c15e3152114 100644 (file)
--- a/net/mac80211/he.c
+++ b/net/mac80211/he.c
@@ -72,12 +72,13 @@ ieee80211_he_spr_ie_to_bss_conf(struct ieee80211_vif *vif,
 {
        struct ieee80211_he_obss_pd *he_obss_pd =
                                        &vif->bss_conf.he_obss_pd;
-       const u8 *data = he_spr_ie_elem->optional;
+       const u8 *data;
 
        memset(he_obss_pd, 0, sizeof(*he_obss_pd));
 
        if (!he_spr_ie_elem)
                return;
+       data = he_spr_ie_elem->optional;
 
        if (he_spr_ie_elem->he_sr_control &
            IEEE80211_HE_SPR_NON_SRG_OFFSET_PRESENT)