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[04/16] wifi: mac80211: mlme: fix non-inheritence element

Message ID 20230604120651.3addaa5c4782.If3a78f9305997ad7ef4ba7ffc17a8234c956f613@changeid (mailing list archive)
State Accepted
Delegated to: Johannes Berg
Headers show
Series cfg80211/mac80211 patches from our internal tree 2023-06-04 | expand

Commit Message

Greenman, Gregory June 4, 2023, 9:11 a.m. UTC 
From: Johannes Berg <johannes.berg@intel.com>

There were two bugs when creating the non-inheritence
element:
 1) 'at_extension' needs to be declared outside the loop,
    otherwise the value resets every iteration and we
    can never really switch properly
 2) 'added' never got set to true, so we always cut off
    the extension element again at the end of the function

This shows another issue that we might add a list but no
extension list, but we need to make the extension list a
zero-length one in that case.

Fix all these issues. While at it, add a comment explaining
the trim.

Fixes: 81151ce462e5 ("wifi: mac80211: support MLO authentication/association with one link")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
---
 net/mac80211/mlme.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 4ea383aafcac..97671734427c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1217,6 +1217,7 @@  static void ieee80211_add_non_inheritance_elem(struct sk_buff *skb,
 					       const u16 *inner)
 {
 	unsigned int skb_len = skb->len;
+	bool at_extension = false;
 	bool added = false;
 	int i, j;
 	u8 *len, *list_len = NULL;
@@ -1228,7 +1229,6 @@  static void ieee80211_add_non_inheritance_elem(struct sk_buff *skb,
 	for (i = 0; i < PRESENT_ELEMS_MAX && outer[i]; i++) {
 		u16 elem = outer[i];
 		bool have_inner = false;
-		bool at_extension = false;
 
 		/* should at least be sorted in the sense of normal -> ext */
 		WARN_ON(at_extension && elem < PRESENT_ELEM_EXT_OFFS);
@@ -1257,8 +1257,14 @@  static void ieee80211_add_non_inheritance_elem(struct sk_buff *skb,
 		}
 		*list_len += 1;
 		skb_put_u8(skb, (u8)elem);
+		added = true;
 	}
 
+	/* if we added a list but no extension list, make a zero-len one */
+	if (added && (!at_extension || !list_len))
+		skb_put_u8(skb, 0);
+
+	/* if nothing added remove extension element completely */
 	if (!added)
 		skb_trim(skb, skb_len);
 	else