diff mbox series

mac80211: validate extended element ID is present

Message ID 20211211201023.f30a1b128c07.I5cacc176da94ba316877c6e10fe3ceec8b4dbd7d@changeid
State New
Headers show
Series mac80211: validate extended element ID is present | expand

Commit Message

Johannes Berg Dec. 11, 2021, 7:10 p.m. UTC 
From: Johannes Berg <johannes.berg@intel.com>

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
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/util.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

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: