[PATCH bpf-next v4 1/3] net: Enlarge offset check value from 0xffff to INT_MAX in bpf_skb_load_bytes

[Liu Jian <liujian56@huawei.com>]

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: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Acked-by: Song Liu <songliubraving@fb.com>
---
v3->v4: delete "|| len > INT_MAX"
 net/core/filter.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 64470a727ef7..966796b345e7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1687,7 +1687,7 @@ 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;
@@ -1722,7 +1722,7 @@ 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);
-- 
2.17.1