| Message ID | 20220411130255.385520-2-liujian56@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | Enlarge offset check value in bpf_skb_load_bytes | expand |
> On Apr 11, 2022, at 6:02 AM, Liu Jian <liujian56@huawei.com> wrote: > > The data length of skb frags + frag_list may be greater than 0xffff, > and skb_header_pointer can not handle negative offset and negative len. > So here INT_MAX is used to check the validity of offset and len. > 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>
diff --git a/net/core/filter.c b/net/core/filter.c index a7044e98765e..b0a3b6489701 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 || len > 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 || len > INT_MAX)) goto err_clear; ptr = skb_header_pointer(skb, offset, len, to);
The data length of skb frags + frag_list may be greater than 0xffff, and skb_header_pointer can not handle negative offset and negative len. So here INT_MAX is used to check the validity of offset and len. 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> --- net/core/filter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)