The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 768c0b19b50665e337c96858aa2b7928d6dcf756 Mon Sep 17 00:00:00 2001
From: Johannes Berg johannes.berg@intel.com Date: Sat, 11 Dec 2021 20:10:24 +0100 Subject: [PATCH] mac80211: validate extended element ID is present
Before attempting to parse an extended element, verify that the extended element ID is present.
Fixes: 41cbb0f5a295 ("mac80211: add support for HE") Reported-by: syzbot+59bdff68edce82e393b6@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20211211201023.f30a1b128c07.I5cacc176da94ba316877c... Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg johannes.berg@intel.com
diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 43df2f0c5db9..6c2934854d3c 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -943,7 +943,12 @@ static void ieee80211_parse_extension_element(u32 *crc, struct ieee802_11_elems *elems) { const void *data = elem->data + 1; - u8 len = elem->datalen - 1; + u8 len; + + if (!elem->datalen) + return; + + len = elem->datalen - 1;
switch (elem->data[0]) { case WLAN_EID_EXT_HE_MU_EDCA: