From: Eric Dumazet <eric.dumazet@gmail.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>
Cc: netdev <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
Jakub Sitnicki <jakub@cloudflare.com>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, KP Singh <kpsingh@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Neal Cardwell <ncardwell@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
syzbot <syzkaller@googlegroups.com>
Subject: [PATCH net 1/2] bpf, sockmap: Do not ignore orig_len parameter
Date: Wed, 2 Mar 2022 08:17:22 -0800 [thread overview]
Message-ID: <20220302161723.3910001-1-eric.dumazet@gmail.com> (raw)
From: Eric Dumazet <edumazet@google.com>
Currently, sk_psock_verdict_recv() returns skb->len
This is problematic because tcp_read_sock() might have
passed orig_len < skb->len, due to the presence of TCP urgent data.
This causes an infinite loop from tcp_read_sock()
Followup patch will make tcp_read_sock() more robust vs bad actors.
Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Tested-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
---
net/core/skmsg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 8eb671c827f90f1f3d2514163fc82998c9906cb6..929a2b096b04e01b85bff0a69209413abe86102d 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -1153,7 +1153,7 @@ static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb,
struct sk_psock *psock;
struct bpf_prog *prog;
int ret = __SK_DROP;
- int len = skb->len;
+ int len = orig_len;
/* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */
skb = skb_clone(skb, GFP_ATOMIC);
--
2.35.1.574.g5d30c73bfb-goog
next reply other threads:[~2022-03-02 16:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-02 16:17 Eric Dumazet [this message]
2022-03-02 16:17 ` [PATCH net 2/2] tcp: make tcp_read_sock() more robust Eric Dumazet
2022-03-03 7:00 ` [PATCH net 1/2] bpf, sockmap: Do not ignore orig_len parameter patchwork-bot+netdevbpf
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