[PATCH 4.2 005/134] NFC: st-nci: fix use of uninitialized variables in error path

[Greg Kroah-Hartman]

4.2-stable review patch.  If anyone has any objections, please let me know.

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

From: Christophe Ricard <christophe.ricard@xxxxxxxxx>

commit daaf1e1f1640eb11259954d1d847d8a72ab5b938 upstream.

st_nci_hci_load_session() calls kfree_skb() on unitialized
variables skb_pipe_info and skb_pipe_list if the call to
nci_hci_connect_gate() failed. Reword the error path to not use
these variables when they are not initialized. While at it, there
seemed to be a memory leak because skb_pipe_info was only freed
once, after the for-loop, even though several ones were created
by nci_hci_send_cmd.

Acked-by: Christophe Ricard <christophe-h.ricard@xxxxxx>
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/nfc/st-nci/st-nci_se.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/nfc/st-nci/st-nci_se.c
+++ b/drivers/nfc/st-nci/st-nci_se.c
@@ -189,14 +189,14 @@ int st_nci_hci_load_session(struct nci_d
 				ST_NCI_DEVICE_MGNT_GATE,
 				ST_NCI_DEVICE_MGNT_PIPE);
 	if (r < 0)
-		goto free_info;
+		return r;
 
 	/* Get pipe list */
 	r = nci_hci_send_cmd(ndev, ST_NCI_DEVICE_MGNT_GATE,
 			ST_NCI_DM_GETINFO, pipe_list, sizeof(pipe_list),
 			&skb_pipe_list);
 	if (r < 0)
-		goto free_info;
+		return r;
 
 	/* Complete the existing gate_pipe table */
 	for (i = 0; i < skb_pipe_list->len; i++) {
@@ -222,6 +222,7 @@ int st_nci_hci_load_session(struct nci_d
 		    dm_pipe_info->src_host_id != ST_NCI_ESE_HOST_ID) {
 			pr_err("Unexpected apdu_reader pipe on host %x\n",
 			       dm_pipe_info->src_host_id);
+			kfree_skb(skb_pipe_info);
 			continue;
 		}
 
@@ -241,13 +242,12 @@ int st_nci_hci_load_session(struct nci_d
 			ndev->hci_dev->pipes[st_nci_gates[j].pipe].host =
 						dm_pipe_info->src_host_id;
 		}
+		kfree_skb(skb_pipe_info);
 	}
 
 	memcpy(ndev->hci_dev->init_data.gates, st_nci_gates,
 	       sizeof(st_nci_gates));
 
-free_info:
-	kfree_skb(skb_pipe_info);
 	kfree_skb(skb_pipe_list);
 	return r;
 }


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