| Message ID | 20220207171319.157775-3-atenart@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9eeabdf17fa0ab75381045c867c370f4cc75a613 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: fix issues when uncloning an skb dst+metadata | expand |
diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h index b997e0c1e362..adab27ba1ecb 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; }
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> --- include/net/dst_metadata.h | 1 - 1 file changed, 1 deletion(-)