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| author | Lv Yunlong <lyl2019@mail.ustc.edu.cn> | 2021-03-28 00:30:29 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-14 08:22:35 +0200 |
| commit | b89b5b030c1ea2ce4811766faadec0ee49d793b2 (patch) | |
| tree | 4c59440a2d02e2ce00e17cef27fa1c2771913e95 | |
| parent | 1b4c7879af6e9c96d318dce37008168ffb216918 (diff) | |
| download | linux-stable-b89b5b030c1ea2ce4811766faadec0ee49d793b2.tar.gz linux-stable-b89b5b030c1ea2ce4811766faadec0ee49d793b2.tar.bz2 linux-stable-b89b5b030c1ea2ce4811766faadec0ee49d793b2.zip | |
net:tipc: Fix a double free in tipc_sk_mcast_rcv
[ Upstream commit 6bf24dc0cc0cc43b29ba344b66d78590e687e046 ]
In the if(skb_peek(arrvq) == skb) branch, it calls __skb_dequeue(arrvq) to get
the skb by skb = skb_peek(arrvq). Then __skb_dequeue() unlinks the skb from arrvq
and returns the skb which equals to skb_peek(arrvq). After __skb_dequeue(arrvq)
finished, the skb is freed by kfree_skb(__skb_dequeue(arrvq)) in the first time.
Unfortunately, the same skb is freed in the second time by kfree_skb(skb) after
the branch completed.
My patch removes kfree_skb() in the if(skb_peek(arrvq) == skb) branch, because
this skb will be freed by kfree_skb(skb) finally.
Fixes: cb1b728096f54 ("tipc: eliminate race condition at multicast reception")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/tipc/socket.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 16e2af3a00cc..4c35f9893081 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1187,7 +1187,7 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq, spin_lock_bh(&inputq->lock); if (skb_peek(arrvq) == skb) { skb_queue_splice_tail_init(&tmpq, inputq); - kfree_skb(__skb_dequeue(arrvq)); + __skb_dequeue(arrvq); } spin_unlock_bh(&inputq->lock); __skb_queue_purge(&tmpq); |