From f38499ff45f567c932d0911e6a30b8ca022b9b52 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Wed, 5 Nov 2025 21:19:40 +0100 Subject: bpf: Unclone skb head on bpf_dynptr_write to skb metadata Currently bpf_dynptr_from_skb_meta() marks the dynptr as read-only when the skb is cloned, preventing writes to metadata. Remove this restriction and unclone the skb head on bpf_dynptr_write() to metadata, now that the metadata is preserved during uncloning. This makes metadata dynptr consistent with skb dynptr, allowing writes regardless of whether the skb is cloned. Signed-off-by: Jakub Sitnicki Signed-off-by: Martin KaFai Lau Link: https://patch.msgid.link/20251105-skb-meta-rx-path-v4-3-5ceb08a9b37b@cloudflare.com --- include/linux/filter.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux') diff --git a/include/linux/filter.h b/include/linux/filter.h index e116de7edc58..a104b3994230 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1781,6 +1781,8 @@ int __bpf_xdp_store_bytes(struct xdp_buff *xdp, u32 offset, void *buf, u32 len); void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset, u32 len); void bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off, void *buf, unsigned long len, bool flush); +int __bpf_skb_meta_store_bytes(struct sk_buff *skb, u32 offset, + const void *from, u32 len, u64 flags); void *bpf_skb_meta_pointer(struct sk_buff *skb, u32 offset); #else /* CONFIG_NET */ static inline int __bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, @@ -1817,6 +1819,13 @@ static inline void bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off, voi { } +static inline int __bpf_skb_meta_store_bytes(struct sk_buff *skb, u32 offset, + const void *from, u32 len, + u64 flags) +{ + return -EOPNOTSUPP; +} + static inline void *bpf_skb_meta_pointer(struct sk_buff *skb, u32 offset) { return ERR_PTR(-EOPNOTSUPP); -- cgit v1.2.3