On HID report descriptor parsing error the code displays bogus
pointer instead of error offset (subtracts start=NULL from end).
Make the message more useful by displaying correct error offset
and include total buffer size for reference.
This is present since ancient times - "Fixed" commit just
promoted the message from DEBUG to ERROR.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 8c3d52fc393b ("HID: make parser more verbose about parsing errors by default")
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
---
* against v5.1.13
---
drivers/hid/hid-core.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 39eba8106d40..88b8db620b4a 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1142,6 +1142,7 @@ int hid_open_report(struct hid_device *device)
__u8 *start;
__u8 *buf;
__u8 *end;
+ __u8 *next;
int ret;
static int (*dispatch_type[])(struct hid_parser *parser,
struct hid_item *item) = {
@@ -1195,7 +1196,8 @@ int hid_open_report(struct hid_device *device)
device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
ret = -EINVAL;
- while ((start = fetch_item(start, end, &item)) != NULL) {
+ while ((next = fetch_item(start, end, &item)) != NULL) {
+ start = next;
if (item.format != HID_ITEM_FORMAT_SHORT) {
hid_err(device, "unexpected long global item\n");
@@ -1233,7 +1235,8 @@ int hid_open_report(struct hid_device *device)
}
}
- hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
+ hid_err(device, "item fetching failed at offset %zu/%zu\n",
+ size - (end - start), size);
err:
kfree(parser->collection_stack);
alloc_err:
--
2.20.1
