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Commit 22771d30 authored by Liu Jian's avatar Liu Jian Committed by Greg Kroah-Hartman
Browse files

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: 05c74e5e ("bpf: add bpf_skb_load_bytes helper")
Signed-off-by: default avatarLiu Jian <liujian56@huawei.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220416105801.88708-2-liujian56@huawei.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ef481b26

net/core/filter.c

+2 −2
Original line number Diff line number Diff line
@@ -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);