From: Cong Wang <xiyou.wangcong@gmail.com>
To: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org, Cong Wang <cong.wang@bytedance.com>,
John Fastabend <john.fastabend@gmail.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Jakub Sitnicki <jakub@cloudflare.com>,
Lorenz Bauer <lmb@cloudflare.com>
Subject: [Patch bpf v2 3/7] udp: fix a memory leak in udp_read_sock()
Date: Sat, 22 May 2021 12:14:07 -0700 [thread overview]
Message-ID: <20210522191411.21446-4-xiyou.wangcong@gmail.com> (raw)
In-Reply-To: <20210522191411.21446-1-xiyou.wangcong@gmail.com>
From: Cong Wang <cong.wang@bytedance.com>
sk_psock_verdict_recv() clones the skb and uses the clone
afterward, so udp_read_sock() should free the skb after using
it, regardless of error or not.
This fixes a real kmemleak.
Fixes: d7f571188ecf ("udp: Implement ->read_sock() for sockmap")
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
net/ipv4/udp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 15f5504adf5b..e31d67fd5183 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1798,11 +1798,13 @@ int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
if (used <= 0) {
if (!copied)
copied = used;
+ kfree_skb(skb);
break;
} else if (used <= skb->len) {
copied += used;
}
+ kfree_skb(skb);
if (!desc->count)
break;
}
--
2.25.1
next prev parent reply other threads:[~2021-05-22 19:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-22 19:14 [Patch bpf v2 0/7] sock_map: some bug fixes and improvements Cong Wang
2021-05-22 19:14 ` [Patch bpf v2 1/7] skmsg: improve udp_bpf_recvmsg() accuracy Cong Wang
2021-05-22 19:14 ` [Patch bpf v2 2/7] selftests/bpf: Retry for EAGAIN in udp_redir_to_connected() Cong Wang
2021-05-22 19:14 ` Cong Wang [this message]
2021-05-22 19:14 ` [Patch bpf v2 4/7] skmsg: fix a memory leak in sk_psock_verdict_apply() Cong Wang
2021-05-22 19:14 ` [Patch bpf v2 5/7] skmsg: teach sk_psock_verdict_apply() to return errors Cong Wang
2021-05-22 19:14 ` [Patch bpf v2 6/7] skmsg: pass source psock to sk_psock_skb_redirect() Cong Wang
2021-05-22 19:14 ` [Patch bpf v2 7/7] skmsg: increase sk->sk_drops when dropping packets Cong Wang
2021-05-26 4:22 ` John Fastabend
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