From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F0684749C1; Tue, 25 Aug 2026 13:57:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787666260; cv=none; b=KWs9nABo/oU5xoP3yoywnrE7ueTrCVuKdMPV8LrJrfnJHfw09Pep8oZpp6KYg3j9dc9Lok3RBesC/VDJ1msHHzVezD30kXD1eWxF+mOjhp22LK9Pt405OWNumkPabs2D2CdOgS4pGDVv3fOXMxtqmK2+xV+pwz7uuYlZ28bbjlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787666260; c=relaxed/simple; bh=P/mGyZf8m9/3LZ/mW5INOngdOyPMFr5LkTYHeAn154g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Oq9kPUSULkN6I1M+RHtyJyIUU6D2LqCWHa/pqDYW/i6xpgzuIBOPb1e/Xmy0m4gEyC8iuQy1dIqzyeWEfNQeKwys58P52rHkNtmCSqwQMowo9jJ/603E0+lZ4LkGF3Nyt8iABDSnkxqw6XgWVZg8yvvyi4HPV7NxKRdQuU/AQaU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=C6WUTQsX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="C6WUTQsX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 583E01F000E9; Tue, 25 Aug 2026 13:57:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787666258; bh=AbCWTmgpYNHGaFegB18nIV85aDT58yp9b7WKf4x1kKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=C6WUTQsXBniY/ZzeEj3KQxG88jZh92b7c3GRHZ2YErpqF7MEHhgpiGGfwFbqZqfUo dF6tCWJaQxXXZlbkpFgexfZHy4lZ/eR7AWr5mzJ0HGrGhsdXwIjhsZgQOXcdTkxLUr +4tucS3K/k5ec2+wompI6xfQluxB6X3UHMeW1Pas= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Jose=20Villase=C3=B1or=20Montfort?= , Alec Hall , Jiri Kosina Subject: [PATCH 5.15 59/76] HID: magicmouse: do not keep a stale msc->input if no input is claimed Date: Tue, 25 Aug 2026 15:26:52 +0200 Message-ID: <20260825132543.891280570@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.568214149@linuxfoundation.org> References: <20260825132541.568214149@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jose Villaseñor Montfort commit 0af3b89705688af01aa06025b84fa7a1e06ba6cc upstream. magicmouse_input_mapping() caches the first hid_input's input_dev in msc->input while the report descriptor is parsed, and the rest of the driver treats a non-NULL msc->input as proof that an input device was registered. That does not hold on the hid-input error path. If hidinput_connect() fails -- for instance because input_register_device() returns an error -- it unwinds through hidinput_disconnect(), which frees every input_dev it created, including the one cached in msc->input. The failure does not abort the probe. hid_connect() only skips the claim: if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev, connect_mask & HID_CONNECT_HIDINPUT_FORCE)) hdev->claimed |= HID_CLAIMED_INPUT; and the "device has no listeners" bailout below it does not fire for this driver, which sets ->raw_event; on the USB Magic Mouse 2 / Magic Trackpad 2 paths hidraw and hiddev are claimed as well. hid_hw_start() therefore returns 0 and magicmouse_probe() continues with msc->input pointing at freed memory. Being non-NULL, it passes the "input not registered" check in probe and the NULL checks in ->raw_event and ->event, so the next input report dereferences freed memory. Clear msc->input when the HID core did not claim an input device, so the existing NULL checks cover this case as well. Fixes: f1a9a149abc8 ("HID: magicmouse: fix race between input_register() and probe()") Link: https://lore.kernel.org/linux-input/20260728185542.65F091F000E9@smtp.kernel.org/ Cc: stable@vger.kernel.org Signed-off-by: Jose Villaseñor Montfort Reviewed-by: Alec Hall Tested-by: Alec Hall Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hid-magicmouse.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/hid/hid-magicmouse.c +++ b/drivers/hid/hid-magicmouse.c @@ -830,6 +830,16 @@ static int magicmouse_probe(struct hid_d return ret; } + /* + * When hidinput_connect() fails it frees every input device it + * created, but that does not fail hid_hw_start(): the core simply + * does not claim an input. msc->input, cached in ->input_mapping + * while the report descriptor was parsed, would then be a dangling + * pointer that passes every NULL check. Trust the core's claim. + */ + if (!(hdev->claimed & HID_CLAIMED_INPUT)) + msc->input = NULL; + if (is_usb_magicmouse2(id->vendor, id->product) || is_usb_magictrackpad2(id->vendor, id->product)) { timer_setup(&msc->battery_timer, magicmouse_battery_timer_tick, 0);