From: Liu Jian <liujian56@huawei.com>
To: <ast@kernel.org>, <daniel@iogearbox.net>, <andrii@kernel.org>,
<kafai@fb.com>, <songliubraving@fb.com>, <yhs@fb.com>,
<john.fastabend@gmail.com>, <kpsingh@kernel.org>,
<davem@davemloft.net>, <kuba@kernel.org>, <sdf@google.com>,
<netdev@vger.kernel.org>, <bpf@vger.kernel.org>
Cc: <liujian56@huawei.com>
Subject: [PATCH bpf-next] net: Use skb->len to check the validity of the parameters in bpf_skb_load_bytes
Date: Tue, 15 Mar 2022 20:39:16 +0800 [thread overview]
Message-ID: <20220315123916.110409-1-liujian56@huawei.com> (raw)
The data length of skb frags + frag_list may be greater than 0xffff,
so here use skb->len to check the validity of the parameters.
And modify bpf_flow_dissector_load_bytes and bpf_skb_load_bytes_relative
in the same way.
Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper")
Fixes: 4e1ec56cdc59 ("bpf: add skb_load_bytes_relative helper")
Fixes: 089b19a9204f ("flow_dissector: switch kernel context to struct bpf_flow_dissector")
Signed-off-by: Liu Jian <liujian56@huawei.com>
---
net/core/filter.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 9eb785842258..61c353caf141 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -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 >= skb->len))
goto err_clear;
ptr = skb_header_pointer(skb, offset, len, to);
@@ -1753,10 +1753,10 @@ BPF_CALL_4(bpf_flow_dissector_load_bytes,
{
void *ptr;
- if (unlikely(offset > 0xffff))
+ if (unlikely(!ctx->skb))
goto err_clear;
- if (unlikely(!ctx->skb))
+ if (unlikely(offset >= ctx->skb->len))
goto err_clear;
ptr = skb_header_pointer(ctx->skb, offset, len, to);
@@ -1787,7 +1787,7 @@ BPF_CALL_5(bpf_skb_load_bytes_relative, const struct sk_buff *, skb,
u8 *end = skb_tail_pointer(skb);
u8 *start, *ptr;
- if (unlikely(offset > 0xffff))
+ if (unlikely(offset >= skb->len))
goto err_clear;
switch (start_header) {
--
2.17.1
next reply other threads:[~2022-03-15 12:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-15 12:39 Liu Jian [this message]
2022-03-15 19:58 ` [PATCH bpf-next] net: Use skb->len to check the validity of the parameters in bpf_skb_load_bytes Martin KaFai Lau
2022-03-16 1:09 ` liujian (CE)
2022-03-16 4:00 ` John Fastabend
2022-03-16 13:08 ` liujian (CE)
2022-03-16 15:09 ` Stanislav Fomichev
2022-03-17 14:08 ` liujian (CE)
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