From 487e437b8f0922badbe239140e22858538869e40 Mon Sep 17 00:00:00 2001 From: Xuanqiang Luo Date: Thu, 23 Jul 2026 14:04:45 +0800 Subject: [PATCH] bpf: lwt: Fix dst reference leak on reroute failure commit 88c17de85ddb459c3fe1e3c65d61fa366b1cf0a8 upstream. bpf_lwt_xmit_reroute() obtains a referenced dst from the route lookup. When skb_cow_head() fails before that dst is installed on the skb, the error path only frees the skb. The skb still owns its previous dst, so the newly looked up dst reference is leaked. Release the new dst reference before freeing the skb on this error path. Fixes: 3bd0b15281af ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c") Cc: stable@vger.kernel.org Signed-off-by: Xuanqiang Luo Link: https://patch.msgid.link/20260723060445.21926-1-xuanqiang.luo@linux.dev Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/core/lwt_bpf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c index efbd9eecb00d..c5b90a309685 100644 --- a/net/core/lwt_bpf.c +++ b/net/core/lwt_bpf.c @@ -246,8 +246,10 @@ static int bpf_lwt_xmit_reroute(struct sk_buff *skb) * if there is enough header space in skb. */ err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); - if (unlikely(err)) + if (unlikely(err)) { + dst_release(dst); goto err; + } skb_dst_drop(skb); skb_dst_set(skb, dst);