23 Jul
2021
23 Jul
'21
2:18 a.m.
From: Will McVicker <willmcvicker(a)google.com>
stable inclusion
from linux-4.19.178
commit ffca531f71d078c6caf752d64bc2a592f420f7c6
category: bugfix
issue: #I421GE
CVE: CVE-2021-0512
--------------------------------
commit ed9be64eefe26d7d8b0b5b9fa3ffdf425d87a01f upstream.
The HID subsystem allows an "HID report field" to have a different
number of "values" and "usages" when it is allocated. When a field
struct is created, the size of the usage array is guaranteed to be at
least as large as the values array, but it may be larger. This leads to
a potential out-of-bounds write in
__hidinput_change_resolution_multipliers() and an out-of-bounds read in
hidinput_count_leds().
To fix this, let's make sure that both the usage and value arrays are
the same size.
Cc: stable(a)vger.kernel.org
Signed-off-by: Will McVicker <willmcvicker(a)google.com>
Signed-off-by: Jiri Kosina <jkosina(a)suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
Signed-off-by: Yu Changchun <yuchangchun1(a)huawei.com>
---
drivers/hid/hid-core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 05122167d..bde5cef32 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -93,7 +93,7 @@ EXPORT_SYMBOL_GPL(hid_register_report);
* Register a new field for this report.
*/
-static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages,
unsigned values)
+static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
{
struct hid_field *field;
@@ -104,7 +104,7 @@ static struct hid_field *hid_register_field(struct hid_report *report,
unsigned
field = kzalloc((sizeof(struct hid_field) +
usages * sizeof(struct hid_usage) +
- values * sizeof(unsigned)), GFP_KERNEL);
+ usages * sizeof(unsigned)), GFP_KERNEL);
if (!field)
return NULL;
@@ -300,7 +300,7 @@ static int hid_add_field(struct hid_parser *parser, unsigned
report_type, unsign
usages = max_t(unsigned, parser->local.usage_index,
parser->global.report_count);
- field = hid_register_field(report, usages, parser->global.report_count);
+ field = hid_register_field(report, usages);
if (!field)
return 0;
--
2.25.1