diff options
| author | Jakub Sitnicki <jakub@cloudflare.com> | 2025-11-05 23:19:46 +0300 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2025-11-10 21:52:32 +0300 |
| commit | fb206fc3129bc9d4749905d4870ba05dc89126d2 (patch) | |
| tree | d8184610f05ca923e4a77ab73a2ce43e5227f7b4 /net/core | |
| parent | 8cfc172ce28e6559d4d2d1a96df77f0f2d6179d6 (diff) | |
| download | linux-fb206fc3129bc9d4749905d4870ba05dc89126d2.tar.xz | |
bpf: Make bpf_skb_change_head helper metadata-safe
Although bpf_skb_change_head() doesn't move packet data after skb_push(),
skb metadata still needs to be relocated. Use the dedicated helper to
handle it.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251105-skb-meta-rx-path-v4-9-5ceb08a9b37b@cloudflare.com
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 50775c01c456..4124becf8604 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3875,6 +3875,7 @@ static const struct bpf_func_proto sk_skb_change_tail_proto = { static inline int __bpf_skb_change_head(struct sk_buff *skb, u32 head_room, u64 flags) { + const u8 meta_len = skb_metadata_len(skb); u32 max_len = BPF_SKB_MAX_LEN; u32 new_len = skb->len + head_room; int ret; @@ -3884,7 +3885,7 @@ static inline int __bpf_skb_change_head(struct sk_buff *skb, u32 head_room, new_len < skb->len)) return -EINVAL; - ret = skb_cow(skb, head_room); + ret = skb_cow(skb, meta_len + head_room); if (likely(!ret)) { /* Idea for this helper is that we currently only * allow to expand on mac header. This means that @@ -3896,6 +3897,7 @@ static inline int __bpf_skb_change_head(struct sk_buff *skb, u32 head_room, * for redirection into L2 device. */ __skb_push(skb, head_room); + skb_postpush_data_move(skb, head_room, 0); memset(skb->data, 0, head_room); skb_reset_mac_header(skb); skb_reset_mac_len(skb); |