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Date: Thu, 11 Apr 2024 14:00:53 +0100
Message-ID: <86pluwrr3u.wl-maz@kernel.org>
From: Marc Zyngier <maz@kernel.org>
To: Guanrui Huang <guanrui.huang@linux.alibaba.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	shannon.zhao@linux.alibaba.com,
	tglx@linutronix.de,
	yuzenghui@huawei.com
Subject: Re: [PATCH v2] irqchip/gic-v3-its: Fix double free on error
In-Reply-To: <20240411115805.115673-1-guanrui.huang@linux.alibaba.com>
References: <86r0fcrvsz.wl-maz@kernel.org>
	<20240411115805.115673-1-guanrui.huang@linux.alibaba.com>
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On Thu, 11 Apr 2024 12:58:05 +0100,
Guanrui Huang <guanrui.huang@linux.alibaba.com> wrote:
> 
> if (vm != domain->host_data)
> 
> This is just a safety check. It looks unlikely happened.

It's not a safety check. It is just papering over problems. If you
don't trust the vm pointer, why do you trust the domain pointer? Why
do you trust *anything* at all?

> After all, vm is obtained from the args. If the caller has a bug,
> can we check here to avoid possible problems that may arise in later
> code?

If the caller has a bug, please fix the caller. Don't paper over it.

And you can remove the BUG_ON(!vm) which is equally useless.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.