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 352DF488D86; Mon, 31 Aug 2026 14:06:46 +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=1788185207; cv=none; b=Cl0HnG8p0weaa/uXAwPv6l6tqsSFwDS7I/exLmYRdgXq1CrXFz7EMRA2wNVolGZyRRNetdY6Kwsv7oTRgtkwnSSUR4g1guz6E2l1W/fHSnrAc4yuJoixxcgpAworerp1JKs8Qp1xrXCq9h1uO/xGa6GwI9LTIvmBMhj4Fynfuhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788185207; c=relaxed/simple; bh=f7aF4BUPpnnBgW5zkqel57WnI2k6DcHGqMYl5XwvAMU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=frrqFUN7SXJ2+47ezmzteAfVar7bqaHnAMQpj+OFeH2XZg9B+hrXLLFZBBDZ0O0WQvUqojc3h5cnH2uXx1HN0V1ER39T0tv5gDRMZOYwqn0e1ChSpyS69tk3ZnNiemYNAHadEbEPr4DjH5V0oEJJCwRn2dyALVZ7jke3hVtRqas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BTDQkFHq; 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="BTDQkFHq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 750BF1F000E9; Mon, 31 Aug 2026 14:06:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788185206; bh=E0dm7gQ2BSbKwbX7wh/RDp5MCRa9p5FcJaWv2Q9m5RA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BTDQkFHq8lsyrxYZjHCFY4dINmYnifZGtowjsbK3RfbQqUSd+KplslF2kgDyfQKr4 vf6SUKI+nXVTIDqXX+fUV2ruJVuM1jnUODj1CMv+DB+KJquMEty3BUAg7wLM0ygWxc PyL4uBH2NVwlw6T7F5i74wQUS23DMRIIlV/9FaCA= 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 , Sasha Levin Subject: [PATCH 5.10 20/43] HID: magicmouse: do not keep a stale msc->input if no input is claimed Date: Mon, 31 Aug 2026 15:35:28 +0200 Message-ID: <20260831133359.437874578@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133358.571886287@linuxfoundation.org> References: <20260831133358.571886287@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jose Villaseñor Montfort [ Upstream commit 0af3b89705688af01aa06025b84fa7a1e06ba6cc ] 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: Sasha Levin 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 @@ -643,6 +643,16 @@ 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 (!msc->input) { hid_err(hdev, "magicmouse input not registered\n"); ret = -ENOMEM;