HID: check empty report_list in hid_validate_values()

[ Upstream commit b12fece4c64857e5fab4290bf01b2e0317a88456 ]

Add a check for empty report_list in hid_validate_values().
The missing check causes a type confusion when issuing a list_entry()
on an empty report_list.
The problem is caused by the assumption that the device must
have valid report_list. While this will be true for all normal HID
devices, a suitably malicious device can violate the assumption.

Fixes: 1b15d2e5b8 ("HID: core: fix validation of report id 0")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Pietro Borrello 2023-01-16 11:11:24 +00:00 committed by Greg Kroah-Hartman
parent 8a7b9560a3
commit 89e7fe3999

View File

@ -981,8 +981,8 @@ struct hid_report *hid_validate_values(struct hid_device *hid,
* Validating on id 0 means we should examine the first * Validating on id 0 means we should examine the first
* report in the list. * report in the list.
*/ */
report = list_entry( report = list_first_entry_or_null(
hid->report_enum[type].report_list.next, &hid->report_enum[type].report_list,
struct hid_report, list); struct hid_report, list);
} else { } else {
report = hid->report_enum[type].report_id_hash[id]; report = hid->report_enum[type].report_id_hash[id];