Messages in this thread Patch in this message | | | From | Xiyu Yang <> | Subject | [PATCH] net/x25: Fix x25_neigh refcnt leak when reveiving frame | Date | Thu, 23 Apr 2020 13:13:03 +0800 |
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x25_lapb_receive_frame() invokes x25_get_neigh(), which returns a reference of the specified x25_neigh object to "nb" with increased refcnt.
When x25_lapb_receive_frame() returns, local variable "nb" becomes invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one path of x25_lapb_receive_frame(). When pskb_may_pull() returns false, the function forgets to decrease the refcnt increased by x25_get_neigh(), causing a refcnt leak.
Fix this issue by calling x25_neigh_put() when pskb_may_pull() returns false.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> --- net/x25/x25_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/x25/x25_dev.c b/net/x25/x25_dev.c index 00e782335cb0..25bf72ee6cad 100644 --- a/net/x25/x25_dev.c +++ b/net/x25/x25_dev.c @@ -115,8 +115,10 @@ int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, goto drop; } - if (!pskb_may_pull(skb, 1)) + if (!pskb_may_pull(skb, 1)) { + x25_neigh_put(nb); return 0; + } switch (skb->data[0]) { -- 2.7.4
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