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Commit 9c90c0c6 authored by Eric Dumazet's avatar Eric Dumazet Committed by Greg Kroah-Hartman
Browse files

tcp: make tcp_read_sock() more robust 



[ 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: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220302161723.3910001-2-eric.dumazet@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 58984c47

net/ipv4/tcp.c

+6 −4
Original line number Diff line number Diff line
@@ -1669,11 +1669,13 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 
				if (!copied)

					copied = used;

				break;

			} else if (used <= len) {

			}

			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