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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot+4b98281f2401ab849f4b@syzkaller.appspotmail.com,
        "J. Bruce Fields" <bfields@redhat.com>,
        Anna Schumaker <Anna.Schumaker@Netapp.com>
Subject: [PATCH 4.20 079/111] sunrpc: handle ENOMEM in rpcb_getport_async
Date:   Mon, 21 Jan 2019 14:43:13 +0100
Message-Id: <20190121122505.061347362@linuxfoundation.org>
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4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: J. Bruce Fields <bfields@redhat.com>

commit 81c88b18de1f11f70c97f28ced8d642c00bb3955 upstream.

If we ignore the error we'll hit a null dereference a little later.

Reported-by: syzbot+4b98281f2401ab849f4b@syzkaller.appspotmail.com
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/sunrpc/rpcb_clnt.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -771,6 +771,12 @@ void rpcb_getport_async(struct rpc_task
 	case RPCBVERS_3:
 		map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 		map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
+		if (!map->r_addr) {
+			status = -ENOMEM;
+			dprintk("RPC: %5u %s: no memory available\n",
+				task->tk_pid, __func__);
+			goto bailout_free_args;
+		}
 		map->r_owner = "";
 		break;
 	case RPCBVERS_2:
@@ -793,6 +799,8 @@ void rpcb_getport_async(struct rpc_task
 	rpc_put_task(child);
 	return;
 
+bailout_free_args:
+	kfree(map);
 bailout_release_client:
 	rpc_release_client(rpcb_clnt);
 bailout_nofree: