Subject: [PATCH 03/12] gigaset: linearize skb

From: Tilman Schmidt <[email-masked]>
Date: Sun, 6 Sep 2009 20:58:52 +0200 (CEST)

The code of the Gigaset driver assumes that sk_buff-s coming
from the ISDN4Linux subsystem are always linear. Explicitly
calling skb_linearize() is cheap if they are, but much more
robust in case they ever aren't.

Impact: robustness improvement
Signed-off-by: Tilman Schmidt <[email-masked]>
---
 drivers/isdn/gigaset/i4l.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/isdn/gigaset/i4l.c b/drivers/isdn/gigaset/i4l.c
index 9b22f9c..322f16e 100644
--- a/drivers/isdn/gigaset/i4l.c
+++ b/drivers/isdn/gigaset/i4l.c
@@ -51,6 +51,12 @@ static int writebuf_from_LL(int driverID, int channel, int ack,
 		return -ENODEV;
 	}
 	bcs = &cs->bcs[channel];
+
+	/* can only handle linear sk_buffs */
+	if (skb_linearize(skb) < 0) {
+		dev_err(cs->dev, "%s: skb_linearize failed\n", __func__);
+		return -ENOMEM;
+	}
 	len = skb->len;
 
 	gig_dbg(DEBUG_LLDATA,
-- 
1.6.2.1.214.ge986c