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

Greg Kroah-Hartman
2015-09-26T20:58:20Z

From: Christophe Ricard <christophe.ricard@gmail.com>

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@st.com>
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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;
}