bpf: Enlarge offset check value to INT_MAX in bpf_skb_{load,store}_bytes

commit 45969b4152c1752089351cd6836a42a566d49bcf upstream. The data length of skb frags + frag_list may be greater than 0xffff, and skb_header_pointer can not handle negative offset. So, here INT_MAX is used to check the validity of offset. Add the same change to the related function skb_store_bytes. Fixes: 05c74e5 ("bpf: add bpf_skb_load_bytes helper") Signed-off-by: Liu Jian <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Song Liu <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
javashin · Jun 6, 2022 · 22771d3 · 22771d3
1 parent ef481b2
commit 22771d3
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/net/core/filter.c b/net/core/filter.c
@@ -1666,7 +1666,7 @@ BPF_CALL_5(bpf_skb_store_bytes, struct sk_buff *, skb, u32, offset,
 
 	if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM | BPF_F_INVALIDATE_HASH)))
 		return -EINVAL;
-	if (unlikely(offset > 0xffff))
+	if (unlikely(offset > INT_MAX))
 		return -EFAULT;
 	if (unlikely(bpf_try_make_writable(skb, offset + len)))
 		return -EFAULT;
@@ -1701,7 +1701,7 @@ BPF_CALL_4(bpf_skb_load_bytes, const struct sk_buff *, skb, u32, offset,
 {
 	void *ptr;
 
-	if (unlikely(offset > 0xffff))
+	if (unlikely(offset > INT_MAX))
 		goto err_clear;
 
 	ptr = skb_header_pointer(skb, offset, len, to);