[PATCH] ISDN: fix double free bug in isdn_net

From: Jesper Juhl
Date: Sat Aug 12 2006 - 16:44:47 EST

There's double-free bug in

If isdn_writebuf_skb_stub() doesn't handle the entire skb, then it will
have freed the skb that was passed to it and when the code then jumps
to the error label it'll result in a double free of the skb.

The easy way to fix this is to insert an assignment of skb = NULL in the
'if' following the call to isdn_writebuf_skb_stub() so that when the code
at the error label calls dev_kfree_skb(skb); the skb will be NULL and
nothing will happen since dev_kfree_skb() just does a return if passed a

Signed-off-by: Jesper Juhl <jesper.juhl@xxxxxxxxx>

drivers/isdn/i4l/isdn_net.c | 1 +
1 files changed, 1 insertion(+)

--- linux-2.6.18-rc4-orig/drivers/isdn/i4l/isdn_net.c 2006-08-11 00:10:55.000000000 +0200
+++ linux-2.6.18-rc4/drivers/isdn/i4l/isdn_net.c 2006-08-12 22:39:56.000000000 +0200
@@ -1023,6 +1023,7 @@ void isdn_net_writebuf_skb(isdn_net_loca
if (ret != len) {
/* we should never get here */
printk(KERN_WARNING "%s: HL driver queue full\n", lp->name);
+ skb = NULL;
goto error;

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