Commit 89e7fe39 authored Jan 16, 2023 by Pietro Borrello Committed by Greg Kroah-Hartman Feb 06, 2023

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: 1b15d2e5 ("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>

parent 8a7b9560

drivers/hid/hid-core.c

+2 −2

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