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* [PATCH] sctp: Fix sk_buff leak when receiving a datagram
@ 2020-06-13 12:39 Xiyu Yang
  2020-06-13 15:57 ` Neil Horman
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Xiyu Yang @ 2020-06-13 12:39 UTC (permalink / raw)
  To: Vlad Yasevich, Neil Horman, Marcelo Ricardo Leitner,
	David S. Miller, Jakub Kicinski, linux-sctp, netdev,
	linux-kernel
  Cc: yuanxzhang, kjlu, Xiyu Yang, Xin Tan

In sctp_skb_recv_datagram(), the function fetch a sk_buff object from
the receiving queue to "skb" by calling skb_peek() or __skb_dequeue()
and return its reference to the caller.

However, when calling __skb_dequeue() successfully, the function forgets
to hold a reference count of the "skb" object and directly return it,
causing a potential memory leak in the caller function.

Fix this issue by calling refcount_inc after __skb_dequeue()
successfully executed.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
 net/sctp/socket.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index d57e1a002ffc..4c8f0b83efd0 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -8990,6 +8990,8 @@ struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
 				refcount_inc(&skb->users);
 		} else {
 			skb = __skb_dequeue(&sk->sk_receive_queue);
+			if (skb)
+				refcount_inc(&skb->users);
 		}
 
 		if (skb)
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-06-27 10:37 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-13 12:39 [PATCH] sctp: Fix sk_buff leak when receiving a datagram Xiyu Yang
2020-06-13 15:57 ` Neil Horman
2020-06-16  7:58 ` [sctp] cf8d0e3e58: netperf.Throughput_tps -100.0% regression kernel test robot
2020-06-27  7:57 ` [sctp] cf8d0e3e58: WARNING:at_net/ipv4/af_inet.c:#inet_sock_destruct kernel test robot

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