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 67ACD13A24D; Mon, 14 Oct 2024 06:50:57 +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=1728888657; cv=none; b=VX0IlYKMdjVtyLlQPvIWYfEoiNFeQUaGOweF47Bb/EHqtQQukWS87EdEiF8FHJcOE1rG+spbLNnY3MKKJhP221cHda6AePGG9xofDXkjuN59SXtnUizQo6CJhD3W09oXlT4/347YBZL9jg9Yd1418PfuhCCKd4BSMyjxse0zhh0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728888657; c=relaxed/simple; bh=5fwQDtuZJ/Bi5IWJSnGY6namt6pSnRXtrjudA9qIXhQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Q6AIYsiw8+JuzfpC1CcTc6xSbCdlLqzwdyAGxWX5AWZeAfrJIrY81RYIybHLuRLEp9BJWULOV9BTud8MBxskJJPrPIyGbP2rApdb1HvBDVSZqlY9fpgZ5c8mlfv9zamY/3PGinZH4VRPpO4NsXvJuw6dAyUSfU+rBBYgwI1S3ys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OikLSEgx; 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="OikLSEgx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10E4BC4CECE; Mon, 14 Oct 2024 06:50:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728888656; bh=5fwQDtuZJ/Bi5IWJSnGY6namt6pSnRXtrjudA9qIXhQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OikLSEgxvQ/fcEAxUnjoMJaWuQcyDjzgHvleJaYTLT1RavHgsL3i0/Yzy0wNeJrQQ eTEhsKcI3zUd7snnF2VraEuaCezkG5TpwnMA+8VM1eB5QUmjvNugJutc7JG3Ynp3oZ abFprHe8KBSibQM71ElL/fMdt6iYMGBXhYFqMxBzdbfNH1mqUs8wfU4nNbKfo1V5sB 9yOapvIO+Bdkk6AkaDpE6FE6Any7H6oaqogkDm30mwQmJhu3oIG680Kj7eFdNmmvMD xknVzMO2qml7hhuj8oMYZCn6BZMrp4rK3BcZzA8SZx6dQKWHG17xMdSuFm4U6QgQGX YNmHPIIOMAXng== Message-ID: <52ce41b7-72e1-48ad-86e4-5cfac67f8174@kernel.org> Date: Mon, 14 Oct 2024 08:50:50 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] staging: vchiq_arm: Fix missing refcount decrement in error path for fw_node To: Umang Jain , Javier Carrasco , Florian Fainelli , Broadcom internal kernel review list , Greg Kroah-Hartman , Stefan Wahren , Laurent Pinchart Cc: linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20241013-vchiq_arm-of_node_put-v1-1-f72b2a6e47d0@gmail.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 13/10/2024 13:36, Umang Jain wrote: > Hi Javier, > > Thank you for the patch. > > On 13/10/24 4:12 pm, Javier Carrasco wrote: >> An error path was introduced without including the required call to >> of_node_put() to decrement the node's refcount and avoid leaking memory. >> If the call to kzalloc() for 'mgmt' fails, the probe returns without >> decrementing the refcount. >> >> Use the automatic cleanup facility to fix the bug and protect the code >> against new error paths where the call to of_node_put() might be missing >> again. >> >> Cc: stable@vger.kernel.org >> Fixes: 1c9e16b73166 ("staging: vc04_services: vchiq_arm: Split driver static and runtime data") >> Signed-off-by: Javier Carrasco >> --- >> drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> index 27ceaac8f6cc..792cf3a807e1 100644 >> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c >> @@ -1332,7 +1332,8 @@ MODULE_DEVICE_TABLE(of, vchiq_of_match); >> >> static int vchiq_probe(struct platform_device *pdev) >> { >> - struct device_node *fw_node; >> + struct device_node *fw_node __free(device_node) = >> + of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware"); > > How about : > > + struct device_node *fw_node __free(device_node) = NULL; > >> const struct vchiq_platform_info *info; >> struct vchiq_drv_mgmt *mgmt; >> int ret; >> @@ -1341,8 +1342,6 @@ static int vchiq_probe(struct platform_device *pdev) >> if (!info) >> return -EINVAL; >> >> - fw_node = of_find_compatible_node(NULL, NULL, >> - "raspberrypi,bcm2835-firmware"); > > And undo this (i.e. keep the of_find_compatible_node() call here The point of using cleanup is to have constructor and destructor in one place, not split. This is not in the spirit of cleanup. Linus also commented on this and cleanup.h *explicitly* recommends not doing so. It also lead to real bugs from time to time, so no, please do not insist on such weird way. Best regards, Krzysztof