From: Antoine Tenart atenart@kernel.org
[ Upstream commit 9eeabdf17fa0ab75381045c867c370f4cc75a613 ]
When uncloning an skb dst and its associated metadata, a new dst+metadata is allocated and later replaces the old one in the skb. This is helpful to have a non-shared dst+metadata attached to a specific skb.
The issue is the uncloned dst+metadata is initialized with a refcount of 1, which is increased to 2 before attaching it to the skb. When tun_dst_unclone returns, the dst+metadata is only referenced from a single place (the skb) while its refcount is 2. Its refcount will never drop to 0 (when the skb is consumed), leading to a memory leak.
Fix this by removing the call to dst_hold in tun_dst_unclone, as the dst+metadata refcount is already 1.
Fixes: fc4099f17240 ("openvswitch: Fix egress tunnel info.") Cc: Pravin B Shelar pshelar@ovn.org Reported-by: Vlad Buslov vladbu@nvidia.com Tested-by: Vlad Buslov vladbu@nvidia.com Signed-off-by: Antoine Tenart atenart@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/dst_metadata.h | 1 - 1 file changed, 1 deletion(-)
diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h index b997e0c1e3627..adab27ba1ecbf 100644 --- a/include/net/dst_metadata.h +++ b/include/net/dst_metadata.h @@ -137,7 +137,6 @@ static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb) #endif
skb_dst_drop(skb); - dst_hold(&new_md->dst); skb_dst_set(skb, &new_md->dst); return new_md; }