Thread (235 messages) 235 messages, 6 authors, 2016-07-30

[added to the 3.18 stable tree] HID: hiddev: validate num_values for HIDIOCGUSAGES, HIDIOCSUSAGES commands

From: Sasha Levin <hidden>
Date: 2016-07-12 03:02:48
Subsystem: hid core layer, the rest, usb hid/hidbp drivers (usb keyboards, mice, remote controls, ...) · Maintainers: Jiri Kosina, Benjamin Tissoires, Linus Torvalds

From: Scott Bauer <redacted>

This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit 93a2001bdfd5376c3dc2158653034c20392d15c5 ]

This patch validates the num_values parameter from userland during the
HIDIOCGUSAGES and HIDIOCSUSAGES commands. Previously, if the report id was set
to HID_REPORT_ID_UNKNOWN, we would fail to validate the num_values parameter
leading to a heap overflow.

Cc: stable@vger.kernel.org
Signed-off-by: Scott Bauer <redacted>
Signed-off-by: Jiri Kosina <redacted>
Signed-off-by: Sasha Levin <redacted>
---
 drivers/hid/usbhid/hiddev.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 2f1ddca..700145b 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -516,13 +516,13 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd,
 					goto inval;
 			} else if (uref->usage_index >= field->report_count)
 				goto inval;
-
-			else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
-				 (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
-				  uref->usage_index + uref_multi->num_values > field->report_count))
-				goto inval;
 		}
 
+		if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
+		    (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
+		     uref->usage_index + uref_multi->num_values > field->report_count))
+			goto inval;
+
 		switch (cmd) {
 		case HIDIOCGUSAGE:
 			uref->value = field->value[uref->usage_index];
-- 
2.5.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help