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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Miaoqian Lin <linmq006@gmail.com>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        Jiri Kosina <jkosina@suse.cz>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 072/287] HID: elan: Fix potential double free in elan_input_configured
Date:   Mon, 13 Jun 2022 12:08:16 +0200
Message-Id: <20220613094926.054136751@linuxfoundation.org>
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From: Miaoqian Lin <linmq006@gmail.com>

[ Upstream commit 1af20714fedad238362571620be0bd690ded05b6 ]

'input' is a managed resource allocated with devm_input_allocate_device(),
so there is no need to call input_free_device() explicitly or
there will be a double free.

According to the doc of devm_input_allocate_device():
 * Managed input devices do not need to be explicitly unregistered or
 * freed as it will be done automatically when owner device unbinds from
 * its driver (or binding fails).

Fixes: b7429ea53d6c ("HID: elan: Fix memleak in elan_input_configured")
Fixes: 9a6a4193d65b ("HID: Add driver for USB ELAN Touchpad")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hid/hid-elan.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/hid/hid-elan.c b/drivers/hid/hid-elan.c
index 7139227edb28..63077fb23026 100644
--- a/drivers/hid/hid-elan.c
+++ b/drivers/hid/hid-elan.c
@@ -192,7 +192,6 @@ static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
 	ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER);
 	if (ret) {
 		hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
-		input_free_device(input);
 		return ret;
 	}
 
@@ -204,7 +203,6 @@ static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
 		hid_err(hdev, "Failed to register elan input device: %d\n",
 			ret);
 		input_mt_destroy_slots(input);
-		input_free_device(input);
 		return ret;
 	}
 
-- 
2.35.1