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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, Linyu Yuan <linyyuan@codeaurora.com>
Subject: [PATCH 4.4 27/34] usb: gadget: eem: fix wrong eem header operation
Date:   Mon, 14 Jun 2021 12:27:18 +0200
Message-Id: <20210614102642.454007917@linuxfoundation.org>
In-Reply-To: <20210614102641.582612289@linuxfoundation.org>
References: <20210614102641.582612289@linuxfoundation.org>
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From: Linyu Yuan <linyyuan@codeaurora.com>

commit 305f670846a31a261462577dd0b967c4fa796871 upstream.

when skb_clone() or skb_copy_expand() fail,
it should pull skb with lengh indicated by header,
or not it will read network data and check it as header.

Cc: <stable@vger.kernel.org>
Signed-off-by: Linyu Yuan <linyyuan@codeaurora.com>
Link: https://lore.kernel.org/r/20210608233547.3767-1-linyyuan@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/gadget/function/f_eem.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/gadget/function/f_eem.c
+++ b/drivers/usb/gadget/function/f_eem.c
@@ -498,7 +498,7 @@ static int eem_unwrap(struct gether *por
 			skb2 = skb_clone(skb, GFP_ATOMIC);
 			if (unlikely(!skb2)) {
 				DBG(cdev, "unable to unframe EEM packet\n");
-				continue;
+				goto next;
 			}
 			skb_trim(skb2, len - ETH_FCS_LEN);
 
@@ -509,7 +509,7 @@ static int eem_unwrap(struct gether *por
 			if (unlikely(!skb3)) {
 				DBG(cdev, "unable to realign EEM packet\n");
 				dev_kfree_skb_any(skb2);
-				continue;
+				goto next;
 			}
 			dev_kfree_skb_any(skb2);
 			skb_queue_tail(list, skb3);