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Date:   Wed, 20 Mar 2019 15:13:53 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Tom Zanussi <tzanussi@gmail.com>
Cc:     Pali =?UTF-8?B?Um9ow6Fy?= <pali.rohar@gmail.com>,
        Mario Limonciello <mario.limonciello@dell.com>,
        linux-kernel@vger.kernel.org
Subject: Re: dell_smbios KASAN bug
Message-ID: <20190320151353.1a223c0e@gandalf.local.home>
In-Reply-To: <1553108749.2079.1.camel@gmail.com>
References: <1553106560.2080.5.camel@gmail.com>
        <20190320144146.08ecd5e4@gandalf.local.home>
        <1553108749.2079.1.camel@gmail.com>
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On Wed, 20 Mar 2019 14:05:49 -0500
Tom Zanussi <tzanussi@gmail.com> wrote:

> On Wed, 2019-03-20 at 14:41 -0400, Steven Rostedt wrote:
> > On Wed, 20 Mar 2019 13:29:20 -0500
> > Tom Zanussi <tzanussi@gmail.com> wrote:
> >   
> > > Hi,
> > > 
> > > While looking into an unrelated problem, I hit this KASAN use-
> > > after-
> > > free warning, so thought I'd let you know.
> > > 
> > > I have no idea how to fix it, but let me know if you need more
> > > info.
> > >   
> > 
> > Could you run with debug in the kernel command line, and see if you
> > hit
> > any failed messages from the dell_smbios_init() call?
> >   
> 
> Not much, but this looks relevant:
> 
> [   26.783749] dell_smbios: No SMBIOS backends available (wmi: -19,
> smm: -19)
> [   26.963648] dell_smbios: No dell-smbios drivers are loaded
>

And does this fix you problem?

-- Steve

diff --git a/drivers/platform/x86/dell-smbios-base.c b/drivers/platform/x86/dell-smbios-base.c
index 9dc282ed5a9e..c3825c674522 100644
--- a/drivers/platform/x86/dell-smbios-base.c
+++ b/drivers/platform/x86/dell-smbios-base.c
@@ -619,6 +619,7 @@ static int __init dell_smbios_init(void)
 
 fail_platform_driver:
 	kfree(da_tokens);
+	da_num_tokens = 0;
 	return ret;
 }