skb_try_make_writable() only works on clones and uncloned packets might have their network header in paged fragments. Fixes: d32de98ea70f ("netfilter: nft_fwd_netdev: allow to forward packets via neighbour layer") Fixes: 7d2086871762 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_flow_table_ip.c | 2 +- net/netfilter/nft_fwd_netdev.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index fd56d663cb5b..39b537fa6e51 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -524,7 +524,7 @@ static int nf_flow_offload_forward(struct nf_flowtable_ctx *ctx, return 0; } - if (skb_try_make_writable(skb, thoff + ctx->hdrsize)) + if (skb_ensure_writable(skb, thoff + ctx->hdrsize)) return -1; flow_offload_refresh(flow_table, flow, false); diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c index 4bce36c3a6a0..0bc0cf194849 100644 --- a/net/netfilter/nft_fwd_netdev.c +++ b/net/netfilter/nft_fwd_netdev.c @@ -111,7 +111,7 @@ static void nft_fwd_neigh_eval(const struct nft_expr *expr, verdict = NFT_BREAK; goto out; } - if (skb_try_make_writable(skb, sizeof(*iph))) { + if (skb_ensure_writable(skb, sizeof(*iph))) { verdict = NF_DROP; goto out; } @@ -132,7 +132,7 @@ static void nft_fwd_neigh_eval(const struct nft_expr *expr, verdict = NFT_BREAK; goto out; } - if (skb_try_make_writable(skb, sizeof(*ip6h))) { + if (skb_ensure_writable(skb, sizeof(*ip6h))) { verdict = NF_DROP; goto out; } -- 2.47.3