Re: [PATCH] luks2: Continue trying all keyslots even if there are some failures

[Patrick Steinhardt]

On Fri, Aug 19, 2022 at 04:10:44PM +0200, Daniel Kiper wrote:
> On Mon, Aug 15, 2022 at 05:23:15PM +0200, Patrick Steinhardt wrote:
> > On Fri, Jul 22, 2022 at 03:04:50AM -0500, Glenn Washburn wrote:
> > > luks2_get_keyslot can fail for a variety of reasons that do not 
> > > neccesarily
> > > mean the next keyslot should not be tried (eg. a new kdf type). So always
> > > try the next slot. This will make GRUB more resilient to non-spec json 
> > > data
> > > that 3rd party systems may add. We do not care if some of the keyslots are
> > > unusable, only if there is at least one that is.
> > >
> > > Signed-off-by: Glenn Washburn <development@efficientek.com>
> > > ---
> > >  grub-core/disk/luks2.c | 10 +++++++++-
> > >  1 file changed, 9 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
> > > index bf741d70f..d8d3180ed 100644
> > > --- a/grub-core/disk/luks2.c
> > > +++ b/grub-core/disk/luks2.c
> > > @@ -610,7 +610,15 @@ luks2_recover_key (grub_disk_t source,
> > >        grub_errno = GRUB_ERR_NONE;
> > >        ret = luks2_get_keyslot (&keyslot, &digest, &segment, json, 
> > > json_idx);
> > >        if (ret)
> > > - goto err;
> > > + {
> > > +   /*
> > > +    * luks2_get_keyslot can fail for a variety of reasons that do not
> > > +    * neccesarily mean the next keyslot should not be tried (eg. a new
> > > +    * kdf type). So always try the next slot.
> > > +    */
> > > +   grub_dprintf ("luks2", "Failed to get keyslot %" PRIuGRUB_UINT64_T 
> > > "\n", keyslot.idx);
> > > +   continue;
> > > + }
> > >        if (grub_errno != GRUB_ERR_NONE)
> > >     grub_dprintf ("luks2", "Ignoring unhandled error %d from 
> > > luks2_get_keyslot\n", grub_errno);
> > >
> > > --
> > > 2.34.1
> > >
> >
> > Reviewed-by: Patrick Steinhardt <ps@pks.im>
> 
> Thank you for review but I have merged this patch earlier and cannot add
> your RB now... :-(
> 
> Daniel

No worries! I assumed as much when I reviewed this but was too lazy to
check ;)

Patrick

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