Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 11/22] tcp: make tcp_read_sock() more robust | Date | Mon, 21 Mar 2022 14:51:42 +0100 |
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From: Eric Dumazet <edumazet@google.com>
[ Upstream commit e3d5ea2c011ecb16fb94c56a659364e6b30fac94 ]
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> Link: https://lore.kernel.org/r/20220302161723.3910001-2-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 c9f6f28e54f3..a0fd9ef2d2c6 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1657,11 +1657,13 @@ 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 -- 2.34.1
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