linux-kernel - Re: [PATCH v2] efivarfs: Replace invalid slashes with exclamation marks in dentries.

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Date:   Fri, 25 Sep 2020 09:54:04 +0200
From:   Michael Schaller <misch@...gle.com>
To:     Ard Biesheuvel <ardb@...nel.org>
Cc:     Michael Schaller <michael@...aller.de>,
        Matthew Garrett <matthew.garrett@...ula.com>,
        Jeremy Kerr <jk@...abs.org>,
        linux-efi <linux-efi@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] efivarfs: Replace invalid slashes with exclamation
 marks in dentries.

On Fri, Sep 25, 2020 at 9:49 AM Ard Biesheuvel <ardb@...nel.org> wrote:
>
> On Fri, 25 Sep 2020 at 09:45, Michael Schaller <misch@...gle.com> wrote:
> >
> > Without this patch efivarfs_alloc_dentry creates dentries with slashes in
> > their name if the respective EFI variable has slashes in its name. This in
> > turn causes EIO on getdents64, which prevents a complete directory listing
> > of /sys/firmware/efi/efivars/.
> >
> > This patch replaces the invalid shlashes with exclamation marks like
> > kobject_set_name_vargs does for /sys/firmware/efi/vars/ to have consistently
> > named dentries under /sys/firmware/efi/vars/ and /sys/firmware/efi/efivars/.
> >
> > Signed-off-by: Michael Schaller <misch@...gle.com>
>
> Thanks
>
> > Tested-by: Michael Schaller <misch@...gle.com>
>
> I will drop this - in general, it is assumed that you test your own
> patches before sending them to the list, so this is implicit. Also,
> tested-by's given on the list tend to carry more weight than ones that
> are givenin private and added to the patch by the authors themselves.
>
Makes sense. Is anything else needed from my side?
>
> > ---
> >  fs/efivarfs/super.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
> > index 28bb5689333a..15880a68faad 100644
> > --- a/fs/efivarfs/super.c
> > +++ b/fs/efivarfs/super.c
> > @@ -141,6 +141,9 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
> >
> >         name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
> >
> > +       /* replace invalid slashes like kobject_set_name_vargs does for /sys/firmware/efi/vars. */
> > +       strreplace(name, '/', '!');
> > +
> >         inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0,
> >                                    is_removable);
> >         if (!inode)
> > --
> > 2.28.0.681.g6f77f65b4e-goog
> >