hog-lib: Fix crash when receiving UHID_GET_REPORT

If UHID_GET_REPORT is received but a report cannot be found, etc, the
would pass bt_hog as user_data instead of report to get_report_cb
leading to a crash.

Fixes https://github.com/bluez/bluez/issues/112

Signed-off-by: Anuj Jain <anuj01.jain@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>

diff --git a/profiles/input/hog-lib.c b/profiles/input/hog-lib.c
index 6ac14e4..e5e3d3e 100755 (executable)
--- a/profiles/input/hog-lib.c
+++ b/profiles/input/hog-lib.c
@@ -786,11 +786,9 @@ fail:
        set_report_cb(err, NULL, 0, hog);
 }
 
-static void get_report_cb(guint8 status, const guint8 *pdu, guint16 len,
-                                                       gpointer user_data)
+static void report_reply(struct bt_hog *hog, uint8_t status, uint8_t id,
+                                uint16_t len, const uint8_t *data)
 {
-       struct report *report = user_data;
-       struct bt_hog *hog = report->hog;
        struct uhid_event rsp;
        int err;
 
@@ -800,6 +798,31 @@ static void get_report_cb(guint8 status, const guint8 *pdu, guint16 len,
        rsp.type = UHID_GET_REPORT_REPLY;
        rsp.u.get_report_reply.id = hog->getrep_id;
 
+       if (status)
+               goto done;
+
+       if (hog->has_report_id && len > 0) {
+               rsp.u.get_report_reply.size = len + 1;
+               rsp.u.get_report_reply.data[0] = id;
+               memcpy(&rsp.u.get_report_reply.data[1], data, len);
+       } else {
+               rsp.u.get_report_reply.size = len;
+               memcpy(rsp.u.get_report_reply.data, data, len);
+       }
+
+done:
+       rsp.u.get_report_reply.err = status;
+       err = bt_uhid_send(hog->uhid, &rsp);
+       if (err < 0)
+               error("bt_uhid_send: %s", strerror(-err));
+}
+
+static void get_report_cb(guint8 status, const guint8 *pdu, guint16 len,
+                                                       gpointer user_data)
+{
+       struct report *report = user_data;
+       struct bt_hog *hog = report->hog;
+
        if (status != 0) {
                error("Error reading Report value: %s", att_ecode2str(status));
                goto exit;
@@ -820,20 +843,8 @@ static void get_report_cb(guint8 status, const guint8 *pdu, guint16 len,
        --len;
        ++pdu;
 
-       if (hog->has_report_id && len > 0) {
-               rsp.u.get_report_reply.size = len + 1;
-               rsp.u.get_report_reply.data[0] = report->id;
-               memcpy(&rsp.u.get_report_reply.data[1], pdu, len);
-       } else {
-               rsp.u.get_report_reply.size = len;
-               memcpy(rsp.u.get_report_reply.data, pdu, len);
-       }
-
 exit:
-       rsp.u.get_report_reply.err = status;
-       err = bt_uhid_send(hog->uhid, &rsp);
-       if (err < 0)
-               error("bt_uhid_send: %s", strerror(-err));
+       report_reply(hog, status, report->id, len, pdu);
 }
 
 static void get_report(struct uhid_event *ev, void *user_data)
@@ -868,8 +879,8 @@ static void get_report(struct uhid_event *ev, void *user_data)
        return;
 
 fail:
-       /* cancel the request on failure */
-       get_report_cb(err, NULL, 0, hog);
+       /* reply with an error on failure */
+       report_reply(hog, err, 0, 0, NULL);
 }
 
 static bool get_descriptor_item_info(uint8_t *buf, ssize_t blen, ssize_t *len,