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 A725D1E47A8; Mon, 14 Jul 2025 11:23:24 +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=1752492204; cv=none; b=ehQUWMV/TS61YZgHoHgI7kf7q1OudbEoOcBWhlODcpBCh9VCJne2qEDZsnrWheaxy0EQj7v/XxmKhX2aRXIW98eFUPdVgzkDCg9Q3OU7lfpIxUsTNXVDyJa4zcDCsnwcj43gT98XBWuwqddblEK7E/WN+ghmPUV+BvnFRWnfr/k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752492204; c=relaxed/simple; bh=DY/dmG6LZNxcbok7TxYUWpoHqR8O26mknUUoN8ACEog=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Pund2UdI0t4fzdQS4jOS6Kh04eNIsdJef2t9pGUwLQmQaIVfHoAr0hK9yinmTUYNLmy2ZsHI5PuOlGJEcVu/3Th+iU7R0lvfPtqiHpq5O2YuzeyItyQW5Cac8//lgJ2HgJBKTti1PrjGYMcV3dybccu1fttyWwjJivraT1U9R8I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YYIReyAs; 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="YYIReyAs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 429A9C4CEF4; Mon, 14 Jul 2025 11:23:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752492204; bh=DY/dmG6LZNxcbok7TxYUWpoHqR8O26mknUUoN8ACEog=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YYIReyAs3klRSmt6LYTsKyntQGMMST6uGgl1PMjXnRAetY7AQsoBiwJvrRzLUDJjQ 9+/oIXIjiJhUZxDMMT0hOetBJm/rFzgXsyWvVGoFfG9IorBcVt6IDqTXbarJ0ymFy5 cimWTCGF/JHusIBPqWcXsNf1Dtg0D91D84wCbPQrrmKBW81Tly1rxv0rbBcBMBR/xW Gdo8CS5XaNtkcQnVELn4XZe/Mvm7dITTDR3V/84LWU04Oo8y83I4h6EQpKiAnLWm5R FFZnXmqk6VgYiH19Y5vzqCYtAwD+NKa4L4ZFs7ffUDEQ8RgL2mQkrNuokVSZPW0sT+ /Sf3orGKxjPFw== Date: Mon, 14 Jul 2025 12:23:19 +0100 From: Will Deacon To: Zhang Shurong Cc: sven@kernel.org, j@jannau.net, alyssa@rosenzweig.io, neal@gompa.dev, joro@8bytes.org, robin.murphy@arm.com, asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iommu/dart: add missing put_device() call in apple_dart_of_xlate Message-ID: References: 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: On Sun, Jul 13, 2025 at 12:16:24AM +0800, Zhang Shurong wrote: > The apple_dart_of_xlate() function obtains a platform device reference > via of_find_device_by_node() but doesn't release it with put_device(). > This patch adds proper device reference handling to prevent memory > leaks. > > Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver") > Signed-off-by: Zhang Shurong > --- > drivers/iommu/apple-dart.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c > index 190f28d76615..811bf5176568 100644 > --- a/drivers/iommu/apple-dart.c > +++ b/drivers/iommu/apple-dart.c > @@ -796,8 +796,10 @@ static int apple_dart_of_xlate(struct device *dev, > > if (!cfg) { > cfg = kzalloc(sizeof(*cfg), GFP_KERNEL); > - if (!cfg) > + if (!cfg) { > + put_device(&iommu_pdev->dev); > return -ENOMEM; > + } > /* Will be ANDed with DART capabilities */ > cfg->supports_bypass = true; > } > @@ -805,8 +807,10 @@ static int apple_dart_of_xlate(struct device *dev, > > cfg_dart = cfg->stream_maps[0].dart; > if (cfg_dart) { > - if (cfg_dart->pgsize != dart->pgsize) > + if (cfg_dart->pgsize != dart->pgsize) { > + put_device(&iommu_pdev->dev); > return -EINVAL; > + } > } > > cfg->supports_bypass &= dart->supports_bypass; > @@ -825,6 +829,8 @@ static int apple_dart_of_xlate(struct device *dev, > } > } > > + > + put_device(&iommu_pdev->dev); > return -EINVAL; Why is it correct to retain the reference on the device in the cases where this function returns 0? Will