From: John Fastabend <john.fastabend@gmail.com>
To: ast@kernel.org, jakub@cloudflare.com, daniel@iogearbox.net,
andriin@fb.com, xiyou.wangcong@gmail.com
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, john.fastabend@gmail.com
Subject: [PATCH bpf v4 1/2] bpf, sockmap: fix potential memory leak on unlikely error case
Date: Mon, 12 Jul 2021 12:55:45 -0700 [thread overview]
Message-ID: <20210712195546.423990-2-john.fastabend@gmail.com> (raw)
In-Reply-To: <20210712195546.423990-1-john.fastabend@gmail.com>
If skb_linearize is needed and fails we could leak a msg on the error
handling. To fix ensure we kfree the msg block before returning error.
Found during code review.
Fixes: 4363023d2668e ("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
---
net/core/skmsg.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 9b6160a191f8..15d71288e741 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -508,10 +508,8 @@ static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb,
if (skb_linearize(skb))
return -EAGAIN;
num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len);
- if (unlikely(num_sge < 0)) {
- kfree(msg);
+ if (unlikely(num_sge < 0))
return num_sge;
- }
copied = skb->len;
msg->sg.start = 0;
@@ -530,6 +528,7 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
{
struct sock *sk = psock->sk;
struct sk_msg *msg;
+ int err;
/* If we are receiving on the same sock skb->sk is already assigned,
* skip memory accounting and owner transition seeing it already set
@@ -548,7 +547,10 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
* into user buffers.
*/
skb_set_owner_r(skb, sk);
- return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
+ err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
+ if (err < 0)
+ kfree(msg);
+ return err;
}
/* Puts an skb on the ingress queue of the socket already assigned to the
@@ -559,12 +561,16 @@ static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb
{
struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
struct sock *sk = psock->sk;
+ int err;
if (unlikely(!msg))
return -EAGAIN;
sk_msg_init(msg);
skb_set_owner_r(skb, sk);
- return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
+ err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
+ if (err < 0)
+ kfree(msg);
+ return err;
}
static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
--
2.25.1
next prev parent reply other threads:[~2021-07-12 19:56 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-12 19:55 [PATCH bpf v4 0/2] bpf, sockmap: fix potential memory leak John Fastabend
2021-07-12 19:55 ` John Fastabend [this message]
2021-07-14 0:35 ` [PATCH bpf v4 1/2] bpf, sockmap: fix potential memory leak on unlikely error case Cong Wang
2021-07-12 19:55 ` [PATCH bpf v4 2/2] bpf, sockmap: sk_prot needs inuse_idx set for proc stats John Fastabend
2021-07-13 7:47 ` Jakub Sitnicki
2021-07-14 0:56 ` Cong Wang
2021-07-13 7:47 ` [PATCH bpf v4 0/2] bpf, sockmap: fix potential memory leak Jakub Sitnicki
2021-07-15 18:00 ` patchwork-bot+netdevbpf
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