From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Gen Zhang <blackgod016574@gmail.com>,
linux-efi <linux-efi@vger.kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] efi_64: Fix a missing-check bug in arch/x86/platform/efi/efi_64.c of Linux 5.1
Date: Fri, 17 May 2019 11:24:27 +0200 [thread overview]
Message-ID: <CAKv+Gu_mwFpdtNZm9QMFn69+vOMTOpv9gvuhnBL2NBXvwkhXqg@mail.gmail.com> (raw)
In-Reply-To: <20190517090628.GA4162@zhanggen-UX430UQ>
On Fri, 17 May 2019 at 11:06, Gen Zhang <blackgod016574@gmail.com> wrote:
>
> On Fri, May 17, 2019 at 10:41:28AM +0200, Ard Biesheuvel wrote:
> > Returning an error here is not going to make much difference, given
> > that the caller of efi_call_phys_prolog() does not bother to check it,
> > and passes the result straight into efi_call_phys_epilog(), which
> > happily attempts to dereference it.
> >
> > So if you want to fix this properly, please fix it at the call site as
> > well. I'd prefer to avoid ERR_PTR() and just return NULL for a failed
> > allocation though.
> Hi Ard,
> Thanks for your timely reply!
> I think returning NULL in efi_call_phys_prolog() and checking in
> efi_call_phys_epilog() is much better. But I am confused what to return
> in efi_call_phys_epilog() if save_pgd is NULL. Definitely not return
> -ENOMEM, because efi_call_phys_epilog() returns unsigned long. Could
> please light on me to fix this problem?
If efi_call_phys_prolog() returns NULL, the calling function should
abort and never call efi_call_phys_epilog().
next prev parent reply other threads:[~2019-05-17 9:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190517082633.GA3890@zhanggen-UX430UQ>
2019-05-17 8:41 ` [PATCH] efi_64: Fix a missing-check bug in arch/x86/platform/efi/efi_64.c of Linux 5.1 Ard Biesheuvel
[not found] ` <20190517090628.GA4162@zhanggen-UX430UQ>
2019-05-17 9:24 ` Ard Biesheuvel [this message]
2019-05-17 9:43 ` Gen Zhang
2019-05-23 0:51 ` [PATCH v2] efi_64: Fix a missing-check bug in arch/x86/platform/efi/efi_64.c Gen Zhang
2019-05-24 16:07 ` Ard Biesheuvel
2019-05-25 2:36 ` Gen Zhang
2019-05-25 9:18 ` Ard Biesheuvel
2019-05-25 9:40 ` Gen Zhang
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