linux-kernel - Re: [PATCH v1] platform/x86/dell/dell-rbtn: Fix resources leaking on error path

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Message-ID: <ZIeH4e8icEEAD3Gc@smile.fi.intel.com>
Date:   Tue, 13 Jun 2023 00:02:25 +0300
From:   Andy Shevchenko <andriy.shevchenko@...el.com>
To:     Pali Rohár <pali@...nel.org>
Cc:     Michal Wilczynski <michal.wilczynski@...el.com>,
        linux-acpi@...r.kernel.org, rafael@...nel.org,
        ilpo.jarvinen@...ux.intel.com, hdegoede@...hat.com,
        markgross@...nel.org, fengguang.wu@...el.com,
        dvhart@...ux.intel.com, platform-driver-x86@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] platform/x86/dell/dell-rbtn: Fix resources leaking on
 error path

On Mon, Jun 12, 2023 at 10:58:39PM +0200, Pali Rohár wrote:
> On Monday 12 June 2023 23:52:30 Andy Shevchenko wrote:
> > On Mon, Jun 12, 2023 at 07:52:05PM +0200, Pali Rohár wrote:
> > > On Monday 12 June 2023 12:02:50 Michal Wilczynski wrote:

...

> > > Hello! I'm looking at rbtn_add() function and there is also code:
> > > 
> > > 	rbtn_data = devm_kzalloc(&device->dev, sizeof(*rbtn_data), GFP_KERNEL);
> > > 	if (!rbtn_data)
> > > 		return -ENOMEM;
> > > 
> > > which is called after rbtn_acquire(). So it looks like when kzalloc
> > > fails then there is another leak...
> > 
> > Side note: In that case we would need a devm wrapper on acquire call.
> 
> Does it makes sense to invest time and more resources for these fixes?
> Driver is not used on new Dell machines, so I would not expect new
> users (instead less users, if they start upgrading HW to new Dell
> machines).
> 
> Simple fix for this issue: Just move devm_kzalloc() call before
> rbtn_acquire(true). And call cleanup rbtn_acquire(false) exactly like
> Michal did in this patch.
> 
> I think that this should be enough, should cover all failure paths and
> does not require to introduce new code or new design, which should be
> properly tested for no regression.
> 
> What do you think?

Sounds like a good alternative! Thank you for the review.

-- 
With Best Regards,
Andy Shevchenko