[PATCH net] net: ipv6: rpl_iptunnel: Fix memory leak in rpl_input

From: Justin Iurman
Date: Wed Sep 11 2024 - 13:46:40 EST


Free the skb before returning from rpl_input when skb_cow_head() fails.
Use a "drop" label and goto instructions.

Fixes: a7a29f9c361f ("net: ipv6: add rpl sr tunnel")
Signed-off-by: Justin Iurman <justin.iurman@xxxxxxxxx>
---
net/ipv6/rpl_iptunnel.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c
index 2c83b7586422..db3c19a42e1c 100644
--- a/net/ipv6/rpl_iptunnel.c
+++ b/net/ipv6/rpl_iptunnel.c
@@ -263,10 +263,8 @@ static int rpl_input(struct sk_buff *skb)
rlwt = rpl_lwt_lwtunnel(orig_dst->lwtstate);

err = rpl_do_srh(skb, rlwt);
- if (unlikely(err)) {
- kfree_skb(skb);
- return err;
- }
+ if (unlikely(err))
+ goto drop;

local_bh_disable();
dst = dst_cache_get(&rlwt->cache);
@@ -286,9 +284,13 @@ static int rpl_input(struct sk_buff *skb)

err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
if (unlikely(err))
- return err;
+ goto drop;

return dst_input(skb);
+
+drop:
+ kfree_skb(skb);
+ return err;
}

static int nla_put_rpl_srh(struct sk_buff *skb, int attrtype,
--
2.34.1