Commit b12fece4 authored by Pietro Borrello's avatar Pietro Borrello Committed by Jiri Kosina

HID: check empty report_list in hid_validate_values()

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: default avatarPietro Borrello <borrello@diag.uniroma1.it>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 2a33ad4a
...@@ -993,8 +993,8 @@ struct hid_report *hid_validate_values(struct hid_device *hid, ...@@ -993,8 +993,8 @@ 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];
......
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