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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Andreas Steinmetz <ast@domdv.de>,
        Willem de Bruijn <willemb@google.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.19 25/50] macsec: fix use-after-free of skb during RX
Date:   Fri, 26 Jul 2019 17:25:00 +0200
Message-Id: <20190726152303.159709857@linuxfoundation.org>
In-Reply-To: <20190726152300.760439618@linuxfoundation.org>
References: <20190726152300.760439618@linuxfoundation.org>
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From: Andreas Steinmetz <ast@domdv.de>

[ Upstream commit 095c02da80a41cf6d311c504d8955d6d1c2add10 ]

Fix use-after-free of skb when rx_handler returns RX_HANDLER_PASS.

Signed-off-by: Andreas Steinmetz <ast@domdv.de>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/macsec.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1103,10 +1103,9 @@ static rx_handler_result_t macsec_handle
 	}
 
 	skb = skb_unshare(skb, GFP_ATOMIC);
-	if (!skb) {
-		*pskb = NULL;
+	*pskb = skb;
+	if (!skb)
 		return RX_HANDLER_CONSUMED;
-	}
 
 	pulled_sci = pskb_may_pull(skb, macsec_extra_len(true));
 	if (!pulled_sci) {