Date: Tue, 20 Nov 2018 19:10:11 +0800
From: Michael Chang <mchang@suse.com>
To: The development of GNU GRUB <grub-devel@gnu.org>
Subject: Re: [PATCH v2] verifiers: fix double close on pgp's sig file
	descriptor
Message-ID: <20181120111011.GA10363@mazu>
Mail-Followup-To: The development of GNU GRUB <grub-devel@gnu.org>
References: <20181115101311.GA14991@mazu>
	<20181116140130.bysatoqzek45nnue@tomti.i.net-space.pl>
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On Fri, Nov 16, 2018 at 03:01:30PM +0100, Daniel Kiper wrote:
> On Thu, Nov 15, 2018 at 06:13:11PM +0800, Michael Chang wrote:
> > An error emerged as when I was tesing the verifiers branch, so instead
> > of putting it in pgp prefix, the verifiers is used to reflect what the
> > patch is based on.
> >
> > While running verify_detached, grub aborts with error.
> >
> > verify_detached /@/.snapshots/1/snapshot/boot/grub/grub.cfg
> > /@/.snapshots/1/snapshot/boot/grub/grub.cfg.sig
> >
> > alloc magic is broken at 0x7beea660: 0
> > Aborted. Press any key to exit.
> >
> > The error is caused by sig file desciptor been closed twice, first time
> > in grub_verify_signature() to which it is passed as parameter. Second in
> > grub_cmd_verify_signature() or in whichever opens the sig file
> > decriptor. The second close is not consider as bug to me either, as in
> > common rule of what opens a file has to close it to avoid file
> > descriptor leakage.
> >
> > Afterall the design of grub_verify_signature() makes it diffcult to keep
> > a good trace on opened file descriptor from it's caller. Let's refine
> > the application interface to accept file path rather than descriptor, in
> > this way the caller doesn't have to care about closing the descriptor by
> > delegating it to grub_verify_signature() with full tracing to opened
> > file descriptor by itself.
> >
> > Signed-off-by: Michael Chang <mchang@suse.com>
> 
> Sadly patch does not apply. Could you rebase it on latest master?

OK. The conflict is caused by new blank line inserted by new commit
which is harmless.

> 
> > v1 -> v2:
> >
> >   - drop change in grub_verify_signature_init()
> 
> If you add a blurb to the commit message why it is needed then I am not
> against it. Even to some extent I am happy with it because it makes code
> a bit nicer.

OK. I'll add that in upcoming v3 patch. :)

Thanks,
Michael

> 
> Daniel
> 
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