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>
Subject: [PATCH net 2/2] tcp: make tcp_read_sock() more robust
Date: Wed, 2 Mar 2022 08:17:23 -0800 [thread overview]
Message-ID: <20220302161723.3910001-2-eric.dumazet@gmail.com> (raw)
In-Reply-To: <20220302161723.3910001-1-eric.dumazet@gmail.com>
From: Eric Dumazet <edumazet@google.com>
If recv_actor() returns an incorrect value, tcp_read_sock()
might loop forever.
Instead, issue a one time warning and make sure to make progress.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
---
net/ipv4/tcp.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 02cb275e5487d98b3e124ee102163aac47b2ad6d..28ff2a820f7c935234e5ab7ecd4ed95fb7c5712a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1684,11 +1684,13 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
if (!copied)
copied = used;
break;
- } else if (used <= len) {
- seq += used;
- copied += used;
- offset += used;
}
+ if (WARN_ON_ONCE(used > len))
+ used = len;
+ seq += used;
+ copied += used;
+ offset += used;
+
/* If recv_actor drops the lock (e.g. TCP splice
* receive) the skb pointer might be invalid when
* getting here: tcp_collapse might have deleted it
--
2.35.1.574.g5d30c73bfb-goog
next prev parent 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 [PATCH net 1/2] bpf, sockmap: Do not ignore orig_len parameter Eric Dumazet
2022-03-02 16:17 ` Eric Dumazet [this message]
2022-03-03 7:00 ` patchwork-bot+netdevbpf
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