From 68b54aeff804acceb02f228ea2e28419272c1fb9 Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Tue, 17 Oct 2023 17:49:51 +0200
Subject: [PATCH] tcp_bpf: properly release resources on error paths
In the blamed commit below, I completely forgot to release the acquired
resources before erroring out in the TCP BPF code, as reported by Dan.
Address the issues by replacing the bogus return with a jump to the
relevant cleanup code.
Fixes: 419ce133ab92 ("tcp: allow again tcp_disconnect() when threads are waiting")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/8f99194c698bcef12666f0a9a999c58f8b1cb52c.1697557782.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
net/ipv4/tcp_bpf.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index ba2e921881248..53b0d62fd2c2d 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -307,8 +307,10 @@ static int tcp_bpf_recvmsg_parser(struct sock *sk,
}
data = tcp_msg_wait_data(sk, psock, timeo);
- if (data < 0)
- return data;
+ if (data < 0) {
+ copied = data;
+ goto unlock;
+ }
if (data && !sk_psock_queue_empty(psock))
goto msg_bytes_ready;
copied = -EAGAIN;
@@ -319,6 +321,8 @@ static int tcp_bpf_recvmsg_parser(struct sock *sk,
tcp_rcv_space_adjust(sk);
if (copied > 0)
__tcp_cleanup_rbuf(sk, copied);
+
+unlock:
release_sock(sk);
sk_psock_put(sk, psock);
return copied;
@@ -353,8 +357,10 @@ static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
data = tcp_msg_wait_data(sk, psock, timeo);
- if (data < 0)
- return data;
+ if (data < 0) {
+ ret = data;
+ goto unlock;
+ }
if (data) {
if (!sk_psock_queue_empty(psock))
goto msg_bytes_ready;
@@ -365,6 +371,8 @@ static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
copied = -EAGAIN;
}
ret = copied;
+
+unlock:
release_sock(sk);
sk_psock_put(sk, psock);
return ret;
--
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