From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 D443520E708; Thu, 27 Mar 2025 10:49:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743072552; cv=none; b=lq2T2ioHW2AXOgWzVqBXpVVjjAJHzSV5ntejYDx7kx6Pw7i4GPTZkITkGmgtmmlhkjXY0Jh2FpxExX7ZQPvdRTqpys0rJ5Kue/LdDdSFxzUS61YtgBZ943AZ8oNVNTBH6fnMrBr1q6Rn1gnHOM/NtSsqfYZFZ2wNL2trXSfMTR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743072552; c=relaxed/simple; bh=P3x1nC7kSQVvmwQm9Ec9eNMVj34oIiVnU6SzBUoQOaM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RoUt8iF/TJlB51HquPTaQPs8kUi6NzazhKa5xa7e0b5whCb0wtCTDdWkEn27ar0JL0z/h7R371F7vakMS0kJ/FzHxSEC9CPkrY11buknsCJ1l3O2HMz2nh9z+SbV7MnlFCWj9WNhOQNjI/YkVZ9tbOiewa8oiXzJ9i8R1+d0h+M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=RBkw9r1W; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="RBkw9r1W" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1743072551; x=1774608551; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=P3x1nC7kSQVvmwQm9Ec9eNMVj34oIiVnU6SzBUoQOaM=; b=RBkw9r1W+hLGSvhZjwmHk4ALFh6Vyfllm4OfYjE72K2B2Pkk9Wv0KWN7 qXjl8eskl4EIkHR3i/hU3sVJGTKA6wgw//sQcP/VX5YRid2TAleMEyQYs NQceqGDavyzL7cYDOW7hBObeA7DargmjLlohtzCQW6Q7h/qZJ/WxFhPg3 VRDdNK6DvJz5hIpoTvvbXZmu3CpICvsLfhFvNuAlhtw9n2gFq3gwnCfGg /21juPh1ThcnTD3GU+t0+K4wmu+GPAZYg0ojktVZiyZEn8np45A6lbOsq rcN+RaymDhHZ6ZMBpK9K5pzULzPHxkEyoiCYH0FI+xzFNpZEmVIHcfnXd A==; X-CSE-ConnectionGUID: zfYcrfCYRzyNcqeTlttrMw== X-CSE-MsgGUID: FNO3cuOsQ4qXw7KNEQPnDw== X-IronPort-AV: E=McAfee;i="6700,10204,11385"; a="44286117" X-IronPort-AV: E=Sophos;i="6.14,280,1736841600"; d="scan'208";a="44286117" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2025 03:49:10 -0700 X-CSE-ConnectionGUID: tjidnPEJTvGDfz226/1LtQ== X-CSE-MsgGUID: 92b+NNZ4TeedXS7yQPAKgg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,280,1736841600"; d="scan'208";a="125617787" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2025 03:49:07 -0700 Received: from kekkonen.localdomain (localhost [127.0.0.1]) by kekkonen.fi.intel.com (Postfix) with SMTP id F037C1201BC; Thu, 27 Mar 2025 12:49:03 +0200 (EET) Date: Thu, 27 Mar 2025 10:49:03 +0000 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo From: Sakari Ailus To: Ma Ke Cc: mchehab@kernel.org, hverkuil@xs4all.nl, sebastian.fricke@collabora.com, ribalda@chromium.org, benjamin.gaignard@collabora.com, viro@zeniv.linux.org.uk, bartosz.golaszewski@linaro.org, hljunggr@cisco.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3] media: v4l2-dev: fix error handling in __video_register_device() Message-ID: References: <20250319080248.1746847-1-make24@iscas.ac.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250319080248.1746847-1-make24@iscas.ac.cn> On Wed, Mar 19, 2025 at 04:02:48PM +0800, Ma Ke wrote: > Once device_register() failed, we should call put_device() to > decrement reference count for cleanup. Or it could cause memory leak. > And move callback function v4l2_device_release() and v4l2_device_get() > before put_device(). > > As comment of device_register() says, 'NOTE: _Never_ directly free > @dev after calling this function, even if it returned an error! Always > use put_device() to give up the reference initialized in this function > instead.' > > Found by code review. > > Cc: stable@vger.kernel.org > Fixes: dc93a70cc7f9 ("V4L/DVB (9973): v4l2-dev: use the release callback from device instead of cdev") > Signed-off-by: Ma Ke Reviewed-by: Sakari Ailus -- Sakari Ailus