bpf, sockmap: Fix potential memory leak on unlikely error case
[ Upstream commit 7e6b27a69167f97c56b5437871d29e9722c3e470 ]
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: 4363023d26
("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/bpf/20210712195546.423990-2-john.fastabend@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:

committed by
Greg Kroah-Hartman

parent
e3a9548ae5
commit
715f378f42
@@ -433,10 +433,8 @@ static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb,
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if (skb_linearize(skb))
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return -EAGAIN;
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num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len);
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if (unlikely(num_sge < 0)) {
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kfree(msg);
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if (unlikely(num_sge < 0))
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return num_sge;
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}
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copied = skb->len;
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msg->sg.start = 0;
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@@ -455,6 +453,7 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
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{
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struct sock *sk = psock->sk;
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struct sk_msg *msg;
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int err;
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/* If we are receiving on the same sock skb->sk is already assigned,
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* skip memory accounting and owner transition seeing it already set
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@@ -473,7 +472,10 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
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* into user buffers.
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*/
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skb_set_owner_r(skb, sk);
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return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
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err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
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if (err < 0)
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kfree(msg);
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return err;
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}
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/* Puts an skb on the ingress queue of the socket already assigned to the
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@@ -484,12 +486,16 @@ static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb
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{
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struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
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struct sock *sk = psock->sk;
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int err;
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if (unlikely(!msg))
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return -EAGAIN;
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sk_msg_init(msg);
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skb_set_owner_r(skb, sk);
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return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
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err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
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if (err < 0)
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kfree(msg);
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return err;
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}
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static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
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