From 306d5acbfc66e7cccb4d8f91fc857206b8df80d1 Mon Sep 17 00:00:00 2001
From: Pan Zhang <zhangpan26@huawei.com>
Date: Thu, 19 Dec 2019 10:45:30 +0800
Subject: [PATCH] drivers/hid/hid-multitouch.c: fix a possible null pointer access.
Git-commit: 306d5acbfc66e7cccb4d8f91fc857206b8df80d1
Patch-mainline: v5.5-rc6
References: git-fixes
1002 if ((quirks & MT_QUIRK_IGNORE_DUPLICATES) && mt) {
1003 struct input_mt_slot *i_slot = &mt->slots[slotnum];
1004
1005 if (input_mt_is_active(i_slot) &&
1006 input_mt_is_used(mt, i_slot))
1007 return -EAGAIN;
1008 }
We previously assumed 'mt' could be null (see line 1002).
The following situation is similar, so add a judgement.
Signed-off-by: Pan Zhang <zhangpan26@huawei.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/hid/hid-multitouch.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index f0d4172d5131..362805ddf377 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -1019,7 +1019,7 @@ static int mt_process_slot(struct mt_device *td, struct input_dev *input,
tool = MT_TOOL_DIAL;
else if (unlikely(!confidence_state)) {
tool = MT_TOOL_PALM;
- if (!active &&
+ if (!active && mt &&
input_mt_is_active(&mt->slots[slotnum])) {
/*
* The non-confidence was reported for
--
2.16.4