From: Liu Jian liujian56@huawei.com
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: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper") Signed-off-by: Liu Jian liujian56@huawei.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Song Liu songliubraving@fb.com Link: https://lore.kernel.org/bpf/20220416105801.88708-2-liujian56@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/filter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/core/filter.c +++ b/net/core/filter.c @@ -1666,7 +1666,7 @@ BPF_CALL_5(bpf_skb_store_bytes, struct s
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 str { void *ptr;
- if (unlikely(offset > 0xffff)) + if (unlikely(offset > INT_MAX)) goto err_clear;
ptr = skb_header_pointer(skb, offset, len, to);