[PATCH 5.10 40/67] net: qrtr: fix memory leaks

Greg Kroah-Hartman
2021-08-02T14:00:28Z

From: Pavel Skripkin <paskripkin@gmail.com>

[ Upstream commit 52f3456a96c06760b9bfae460e39596fec7af22e ]

Syzbot reported memory leak in qrtr. The problem was in unputted
struct sock. qrtr_local_enqueue() function calls qrtr_port_lookup()
which takes sock reference if port was found. Then there is the following
check:

if (!ipc || &ipc->sk == skb->sk) {
...
return -ENODEV;
}

Since we should drop the reference before returning from this function and
ipc can be non-NULL inside this if, we should add qrtr_port_put() inside
this if.

The similar corner case is in qrtr_endpoint_post() as Manivannan
reported. In case of sock_queue_rcv_skb() failure we need to put
port reference to avoid leaking struct sock pointer.

Fixes: e04df98adf7d ("net: qrtr: Remove receive worker")
Fixes: bdabad3e363d ("net: Add Qualcomm IPC router")
Reported-and-tested-by: syzbot+35a511c72ea7356cdcf3@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/qrtr/qrtr.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index 0d9baddb9cd4..6826558483f9 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -504,8 +504,10 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
if (!ipc)
goto err;

- if (sock_queue_rcv_skb(&ipc->sk, skb))
+ if (sock_queue_rcv_skb(&ipc->sk, skb)) {
+ qrtr_port_put(ipc);
goto err;
+ }

qrtr_port_put(ipc);
}
@@ -830,6 +832,8 @@ static int qrtr_local_enqueue(struct qrtr_node *node, struct sk_buff *skb,

ipc = qrtr_port_lookup(to->sq_port);
if (!ipc || &ipc->sk == skb->sk) { /* do not send to self */
+ if (ipc)
+ qrtr_port_put(ipc);
kfree_skb(skb);
return -ENODEV;
}
--
2.30.2