HID: core: use __free(kfree) and __free(kvfree) to clean up temporary buffers

This simplifies error handling and protects against memory leaks.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 2c8c9d05e450337932e8314e3a0d0ce746dfecb0..49775e3624ef2dbce3253fb328d29a07f959f02d 100644 (file)
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -924,7 +924,6 @@ static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
  */
 static int hid_scan_report(struct hid_device *hid)
 {
-       struct hid_parser *parser;
        struct hid_item item;
        const __u8 *start = hid->dev_rdesc;
        const __u8 *end = start + hid->dev_rsize;
@@ -936,7 +935,7 @@ static int hid_scan_report(struct hid_device *hid)
                hid_parser_reserved
        };
 
-       parser = vzalloc(sizeof(struct hid_parser));
+       struct hid_parser *parser __free(kvfree) = vzalloc(sizeof(*parser));
        if (!parser)
                return -ENOMEM;
 
@@ -987,7 +986,6 @@ static int hid_scan_report(struct hid_device *hid)
        }
 
        kfree(parser->collection_stack);
-       vfree(parser);
        return 0;
 }
 
@@ -1246,7 +1244,6 @@ EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
 
 static int hid_parse_collections(struct hid_device *device)
 {
-       struct hid_parser *parser;
        struct hid_item item;
        const u8 *start = device->rdesc;
        const u8 *end = start + device->rsize;
@@ -1259,7 +1256,7 @@ static int hid_parse_collections(struct hid_device *device)
                hid_parser_reserved
        };
 
-       parser = vzalloc(sizeof(*parser));
+       struct hid_parser *parser __free(kvfree) = vzalloc(sizeof(*parser));
        if (!parser)
                return -ENOMEM;
 
@@ -1267,10 +1264,9 @@ static int hid_parse_collections(struct hid_device *device)
 
        device->collection = kzalloc_objs(*device->collection,
                                          HID_DEFAULT_NUM_COLLECTIONS);
-       if (!device->collection) {
-               ret = -ENOMEM;
-               goto out;
-       }
+       if (!device->collection)
+               return -ENOMEM;
+
        device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
        for (unsigned int i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
                device->collection[i].parent_idx = -1;
@@ -1322,7 +1318,6 @@ static int hid_parse_collections(struct hid_device *device)
 
 out:
        kfree(parser->collection_stack);
-       vfree(parser);
        return ret;
 }
 
@@ -1358,9 +1353,9 @@ int hid_open_report(struct hid_device *device)
                 * on a copy of our report descriptor so it can
                 * change it.
                 */
-               __u8 *buf = kmemdup(start, size, GFP_KERNEL);
+               u8 *buf __free(kfree) = kmemdup(start, size, GFP_KERNEL);
 
-               if (buf == NULL)
+               if (!buf)
                        return -ENOMEM;
 
                start = device->driver->report_fixup(device, buf, &size);
@@ -1371,8 +1366,7 @@ int hid_open_report(struct hid_device *device)
                 * needs to be cleaned up or not at the end.
                 */
                start = kmemdup(start, size, GFP_KERNEL);
-               kfree(buf);
-               if (start == NULL)
+               if (!start)
                        return -ENOMEM;
        }
 
@@ -1998,11 +1992,11 @@ static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
 int __hid_request(struct hid_device *hid, struct hid_report *report,
                enum hid_class_request reqtype)
 {
-       char *buf, *data_buf;
+       u8 *data_buf;
        int ret;
        u32 len;
 
-       buf = hid_alloc_report_buf(report, GFP_KERNEL);
+       u8 *buf __free(kfree) = hid_alloc_report_buf(report, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;
 
@@ -2021,17 +2015,13 @@ int __hid_request(struct hid_device *hid, struct hid_report *report,
        ret = hid_hw_raw_request(hid, report->id, buf, len, report->type, reqtype);
        if (ret < 0) {
                dbg_hid("unable to complete request: %d\n", ret);
-               goto out;
+               return ret;
        }
 
        if (reqtype == HID_REQ_GET_REPORT)
                hid_input_report(hid, report->type, buf, ret, 0);
 
-       ret = 0;
-
-out:
-       kfree(buf);
-       return ret;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(__hid_request);