From: John Fastabend <john.fastabend@xxxxxxxxx>
[ 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: 4363023d2668e ("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list")
Signed-off-by: John Fastabend <john.fastabend@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Reviewed-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20210712195546.423990-2-john.fastabend@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 923a1d0f84ca..c4c224a5b9de 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -433,10 +433,8 @@ 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;
@@ -455,6 +453,7 @@ 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
@@ -473,7 +472,10 @@ 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
@@ -484,12 +486,16 @@ 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,
--
2.30.2
