linux-kernel - Re: [PATCH v2] efi: fix a race and a buffer overflow while reading efivars via sysfs

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Message-ID: <1322502214.13237657.1583389049605.JavaMail.zimbra@redhat.com>
Date:   Thu, 5 Mar 2020 01:17:29 -0500 (EST)
From:   Vladis Dronov <vdronov@...hat.com>
To:     joeyli <jlee@...e.com>
Cc:     Ard Biesheuvel <ardb@...nel.org>, linux-efi@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] efi: fix a race and a buffer overflow while reading
 efivars via sysfs

Hello, Joey, all,

> > -	var->DataSize = 1024;
> > -	if (efivar_entry_get(entry, &entry->var.Attributes,
> > -			     &entry->var.DataSize, entry->var.Data))
> > +	ret = efivar_entry_get(entry, &var->Attributes, &datasize, var->Data);
> > +	var->DataSize = size;
> 
> The size is indeterminate here. I think that it should uses datasize?
> 	var->DataSize = datasize;

Indeed, my mistake. Thank you much! I will fix it in the v3 patchset I'm
currently composing.

Best regards,
Vladis Dronov | Red Hat, Inc. | The Core Kernel | Senior Software Engineer