gre: fix a possible skb leak
commit 68c331631143 ("v4 GRE: Add TCP segmentation offload for GRE")
added a possible skb leak, because it frees only the head of segment
list, in case a skb_linearize() call fails.
This patch adds a kfree_skb_list() helper to fix the bug.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 9c676eae..dec1748 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -627,6 +627,7 @@
}
extern void kfree_skb(struct sk_buff *skb);
+extern void kfree_skb_list(struct sk_buff *segs);
extern void skb_tx_error(struct sk_buff *skb);
extern void consume_skb(struct sk_buff *skb);
extern void __kfree_skb(struct sk_buff *skb);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index cfd777b..1c1738c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -483,15 +483,8 @@
static void skb_drop_list(struct sk_buff **listp)
{
- struct sk_buff *list = *listp;
-
+ kfree_skb_list(*listp);
*listp = NULL;
-
- do {
- struct sk_buff *this = list;
- list = list->next;
- kfree_skb(this);
- } while (list);
}
static inline void skb_drop_fraglist(struct sk_buff *skb)
@@ -651,6 +644,17 @@
}
EXPORT_SYMBOL(kfree_skb);
+void kfree_skb_list(struct sk_buff *segs)
+{
+ while (segs) {
+ struct sk_buff *next = segs->next;
+
+ kfree_skb(segs);
+ segs = next;
+ }
+}
+EXPORT_SYMBOL(kfree_skb_list);
+
/**
* skb_tx_error - report an sk_buff xmit error
* @skb: buffer that triggered an error
diff --git a/net/ipv4/gre.c b/net/ipv4/gre.c
index b2e805a..7856d16 100644
--- a/net/ipv4/gre.c
+++ b/net/ipv4/gre.c
@@ -178,7 +178,7 @@
err = __skb_linearize(skb);
if (err) {
- kfree_skb(segs);
+ kfree_skb_list(segs);
segs = ERR_PTR(err);
goto out;
}