From b3a81c777dcb093020680490ab970d85e2f6f04f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= Date: Fri, 23 Aug 2019 21:15:27 +0200 Subject: [PATCH] HID: fix error message in hid_open_report() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 was carried over from ancient times - "Fixed" commit just promoted the message from DEBUG to ERROR. Cc: stable@vger.kernel.org Fixes: 8c3d52fc393b ("HID: make parser more verbose about parsing errors by default") Signed-off-by: Michał Mirosław Signed-off-by: Jiri Kosina --- 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 3eaee2c37931..63fdbf09b044 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1139,6 +1139,7 @@ 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) = { @@ -1192,7 +1193,8 @@ 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"); @@ -1230,7 +1232,8 @@ 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 %u/%u\n", + size - (unsigned int)(end - start), size); err: kfree(parser->collection_stack); alloc_err: