linux-kernel - [PATCH 4.9 29/96] cx82310_eth: use skb_cow

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180115123406.986851241@linuxfoundation.org>
Date:   Mon, 15 Jan 2018 13:34:28 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Eric Dumazet <edumazet@...gle.com>,
        James Hughes <james.hughes@...pberrypi.org>,
        "David S. Miller" <davem@...emloft.net>,
        Oliver Neukum <oneukum@...e.com>
Subject: [PATCH 4.9 29/96] cx82310_eth: use skb_cow_head() to deal with cloned skbs

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@...gle.com>

commit a9e840a2081ed28c2b7caa6a9a0041c950b3c37d upstream.

We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.

skb_cow_head() is the proper helper to deal with this.

Fixes: cc28a20e77b2 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver")
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: James Hughes <james.hughes@...pberrypi.org>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Oliver Neukum <oneukum@...e.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/net/usb/cx82310_eth.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

--- a/drivers/net/usb/cx82310_eth.c
+++ b/drivers/net/usb/cx82310_eth.c
@@ -293,12 +293,9 @@ static struct sk_buff *cx82310_tx_fixup(
 {
 	int len = skb->len;

-	if (skb_headroom(skb) < 2) {
-		struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
+	if (skb_cow_head(skb, 2)) {
 		dev_kfree_skb_any(skb);
-		skb = skb2;
-		if (!skb)
-			return NULL;
+		return NULL;
 	}
 	skb_push(skb, 2);