From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BFF2A2AF00; Thu, 23 Apr 2026 05:19:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776921563; cv=none; b=GP38CwTXlmiF095PVmiD2Il6ToxYDXaR+Fd5u+mZ3mFvKKGUiQd1mKM7acTrg981kk3lyP30YE8t8EFToiHOnit3kQzno6VGmrcLg82uajzjotW0H/+P2g0WlKtR3cG9su5WshpChZduMJ83hvQSeGKJzOcfCVZZNB4Su87s5jU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776921563; c=relaxed/simple; bh=XN7WQGeQsEDnRBpXI8hnED/oD5rHGhtUbhNXkc+YPjw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Lql2urOUCEpYvnH28QERdTnIjZDFmFPi3ZOfmpMX9n0frCeuyDZUaIHHuTYFvaVAaGyT3CkAplc1mq/2HNDVUhM9ocn/l0sWo0cLgvjLW2Wk5RYkP7Gq+kYGOTSs0ZGpCpsPJGW8P3mgHVhjFQf8pXwuEaor5V79FgJ4YTJ4WJI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hy6waPCV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hy6waPCV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3AB2C2BCB2; Thu, 23 Apr 2026 05:19:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776921563; bh=XN7WQGeQsEDnRBpXI8hnED/oD5rHGhtUbhNXkc+YPjw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=hy6waPCVD3EhX2+2OymXHrPQSPrCjTMD0XOd0ctOacKWK4ew6Nkas6ZZL9gn8h+1F twMvxDo1FPjFR2plNBwMOl055AQoA+2wM3rqqgLD82k4sS5AfBash5pexwhVqBeIBO Nz6fjfzlKi2g3Fg7ekfCRgRSZ9Q7jGIUZnUSOefjMkqVWeV9owB1XYX/WziDLUPk8s FspoZURkrw37CE/AWAGD13M3eTxkPmfm5TvqBlcU86wM8nJyZn5WlK0q9gz5qID1Jp 9BZ2dZkKIzVBWCEoeixqw6PzphJywhtPjLrPCXF4BHOhT9LT3U4x7M5vCMjVtvXxIp MFOeHtrwNPxXA== Message-ID: Date: Thu, 23 Apr 2026 07:19:20 +0200 Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ALSA: pcmtest: fix reference leak on failed device registration To: Takashi Iwai , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich Cc: Guangshuo Li , linux-kernel@vger.kernel.org, driver-core@lists.linux.dev References: <20260415193138.3861297-1-lgs201920130244@gmail.com> <87h5padnof.wl-tiwai@suse.de> <874il9eu4c.wl-tiwai@suse.de> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: <874il9eu4c.wl-tiwai@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 17. 04. 26, 12:52, Takashi Iwai wrote: > On Fri, 17 Apr 2026 09:57:20 +0200, > Takashi Iwai wrote: >> >> On Wed, 15 Apr 2026 21:31:38 +0200, >> Guangshuo Li wrote: >>> >>> When platform_device_register() fails in mod_init(), the embedded struct >>> device in pcmtst_pdev has already been initialized by >>> device_initialize(), but the failure path returns the error without >>> dropping the device reference for the current platform device: >>> >>> mod_init() >>> -> platform_device_register(&pcmtst_pdev) >>> -> device_initialize(&pcmtst_pdev.dev) >>> -> setup_pdev_dma_masks(&pcmtst_pdev) >>> -> platform_device_add(&pcmtst_pdev) >>> >>> This leads to a reference leak when platform_device_register() fails. >>> Fix this by calling platform_device_put() before returning the error. >>> >>> The issue was identified by a static analysis tool I developed and >>> confirmed by manual review. >>> >>> Fixes: 315a3d57c64c5 ("ALSA: Implement the new Virtual PCM Test Driver") >>> Cc: stable@vger.kernel.org >>> Signed-off-by: Guangshuo Li >> >> Thanks, applied now. > > ... and now I looked through the whole tree, and noticed that the > majority of callers of platform_device_register() don't care the error > cases without calling platform_device_put(). There are over a hundred > callers of platform_device_register() while only 5 or so are doing the > proper cleanup at the error. Moreover, unless the static pcmtst_pdev has ->type->release or ->release set, the patch triggers a warning upon put(). > Judging from the numbers above, it might be better to change the > behavior of platform_device_register() itself to call *_put() at the > error case internally. Yes, that's what should be done instead. thanks, -- js suse labs