Commit bd8a7036 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

gre: fix a possible skb leak 



commit 68c33163 ("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: default avatarEric Dumazet <edumazet@google.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2b7a5db0

include/linux/skbuff.h

+1 −0
Original line number Diff line number Diff line
@@ -627,6 +627,7 @@ static inline struct rtable *skb_rtable(const struct sk_buff *skb) 
}



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);

net/core/skbuff.c

+12 −8
Original line number Diff line number Diff line
@@ -483,15 +483,8 @@ EXPORT_SYMBOL(skb_add_rx_frag); 


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 @@ void kfree_skb(struct sk_buff *skb) 
}

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

net/ipv4/gre.c

+1 −1
Original line number Diff line number Diff line
@@ -178,7 +178,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, 


				err = __skb_linearize(skb);

				if (err) {

					kfree_skb(segs);

					kfree_skb_list(segs);

					segs = ERR_PTR(err);

					goto out;

				}

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