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[for-3.18,15/24] HID: core: prevent out-of-bound readings

Message ID 1494340968-17152-16-git-send-email-amit.pundir@linaro.org
State New
Headers show
Series Security fixes from 2015 and 2016 android security bulletins | expand

Commit Message

Amit Pundir May 9, 2017, 2:42 p.m. UTC 
From: Benjamin Tissoires <benjamin.tissoires@redhat.com>


commit 50220dead1650609206efe91f0cc116132d59b3f upstream.

Plugging a Logitech DJ receiver with KASAN activated raises a bunch of
out-of-bound readings.

The fields are allocated up to MAX_USAGE, meaning that potentially, we do
not have enough fields to fit the incoming values.
Add checks and silence KASAN.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

---
 drivers/hid/hid-core.c | 3 +++
 1 file changed, 3 insertions(+)

-- 
2.7.4
diff mbox series

Patch

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 19a3a12f3257..34dda44cb910 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1213,6 +1213,7 @@  static void hid_input_field(struct hid_device *hid, struct hid_field *field,
 		/* Ignore report if ErrorRollOver */
 		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
 		    value[n] >= min && value[n] <= max &&
+		    value[n] - min < field->maxusage &&
 		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
 			goto exit;
 	}
@@ -1225,11 +1226,13 @@  static void hid_input_field(struct hid_device *hid, struct hid_field *field,
 		}
 
 		if (field->value[n] >= min && field->value[n] <= max
+			&& field->value[n] - min < field->maxusage
 			&& field->usage[field->value[n] - min].hid
 			&& search(value, field->value[n], count))
 				hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
 
 		if (value[n] >= min && value[n] <= max
+			&& value[n] - min < field->maxusage
 			&& field->usage[value[n] - min].hid
 			&& search(field->value, value[n], count))
 				hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);