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From:   Doug Brown <doug@schmorgal.com>
To:     Kalle Valo <kvalo@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org,
        netdev@vger.kernel.org, Doug Brown <doug@schmorgal.com>
Subject: [PATCH] wifi: libertas: return consistent length in lbs_add_wpa_tlv()
Date:   Mon,  2 Jan 2023 15:47:14 -0800
Message-Id: <20230102234714.169831-1-doug@schmorgal.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The existing code only converts the first IE to a TLV, but it returns a
value that takes the length of all IEs into account. When there is more
than one IE (which happens with modern wpa_supplicant versions for
example), the returned length is too long and extra junk TLVs get sent
to the firmware, resulting in an association failure.

Fix this by returning a length that only factors in the single IE that
was converted. The firmware doesn't seem to support the additional IEs,
so there is no value in trying to convert them to additional TLVs.

Fixes: e86dc1ca4676 ("Libertas: cfg80211 support")
Signed-off-by: Doug Brown <doug@schmorgal.com>
---
 drivers/net/wireless/marvell/libertas/cfg.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas/cfg.c b/drivers/net/wireless/marvell/libertas/cfg.c
index 3e065cbb0af9..fcc5420ec7ea 100644
--- a/drivers/net/wireless/marvell/libertas/cfg.c
+++ b/drivers/net/wireless/marvell/libertas/cfg.c
@@ -432,10 +432,9 @@ static int lbs_add_wpa_tlv(u8 *tlv, const u8 *ie, u8 ie_len)
 	*tlv++ = 0;
 	tlv_len = *tlv++ = *ie++;
 	*tlv++ = 0;
-	while (tlv_len--)
-		*tlv++ = *ie++;
-	/* the TLV is two bytes larger than the IE */
-	return ie_len + 2;
+	memcpy(tlv, ie, tlv_len);
+	/* the TLV has a four-byte header */
+	return tlv_len + 4;
 }
 
 /*
-- 
2.34.1