Description: null pointer dereference in nl80211_set_rekey_data()
References:
 https://marc.info/?t=150525503100001&r=1&w=2
 https://marc.info/?l=linux-wireless&m=150525493517953&w=2
Notes:
 bwh> Said to be introduced in 3.1 by commit e5497d766ad ("cfg80211/nl80211:
 bwh> support GTK rekey offload").
Bugs:
upstream: released (4.14-rc2) [e785fa0a164aa11001cba931367c7f94ffaff888]
4.9-upstream-stable: released (4.9.53) [c820441a7a52e3626aede8df94069a50a9e4efdb]
3.16-upstream-stable: released (3.16.49) [ed2305f2eba403d41dc4213746f60d47273980f6]
3.2-upstream-stable: released (3.2.94) [082d8a6a55d2b6583d9e93ac9796efdf4c412658]
sid: released (4.12.13-1) [bugfix/all/nl80211-check-for-the-required-netlink-attributes-presence.patch]
4.9-stretch-security: released (4.9.30-2+deb9u4) [bugfix/all/nl80211-check-for-the-required-netlink-attributes-presence.patch]
3.16-jessie-security: released (3.16.43-2+deb8u4) [bugfix/all/nl80211-check-for-the-required-netlink-attributes-presence.patch]
3.2-wheezy-security: released (3.2.93-1) [bugfix/all/nl80211-check-for-the-required-netlink-attributes-presence.patch]