Re: [PATCH] blsuki: Fix grub_errno leakage in blsuki_is_default_entry()

On Mon, Nov 10, 2025 at 07:05:10PM +0530, Sudhakar Kuppusamy wrote:
> 
> 
> > On 10 Nov 2025, at 1:08 PM, Michael Chang via Grub-devel <[email protected]> wrote:
> > 
> > The grub_strtol() call in blsuki_is_default_entry() can set grub_errno
> > to GRUB_ERR_BAD_NUMBER if the input string cannot be converted into any
> > valid digits.
> > 
> > This errno value is currently left uncleared, which can lead to
> > unexpected behavior in subsequent logic that tests the result of a
> > function by checking grub_errno.
> > 
> > Clear grub_errno and return false when GRUB_ERR_BAD_NUMBER is set, as
> > this specific error should be ignored in this context.
> > 
> > Signed-off-by: Michael Chang <[email protected]>
> 
> Reviewed-by: Sudhakar Kuppusamy <[email protected]>

Thanks for the review. I'll add your Reviewed-by tag in next version.

Thanks,
Michael

> 
> 
> Thanks,
> Sudhakar  
> > ---
> > grub-core/commands/blsuki.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> > 
> > diff --git a/grub-core/commands/blsuki.c b/grub-core/commands/blsuki.c
> > index 21d767f05..df25b6fbc 100644
> > --- a/grub-core/commands/blsuki.c
> > +++ b/grub-core/commands/blsuki.c
> > @@ -1510,6 +1510,12 @@ blsuki_is_default_entry (const char *def_entry, grub_blsuki_entry_t *entry, int
> >     return true;
> > 
> >   def_idx = grub_strtol (def_entry, &def_entry_end, 0);
> > +  if (grub_errno == GRUB_ERR_BAD_NUMBER)
> > +    {
> > +      grub_errno = GRUB_ERR_NONE;
> > +      return false;
> > +    }
> > +
> >   if (*def_entry_end != '\0' || def_idx < 0 || def_idx > GRUB_INT_MAX)
> >     return false;
> > 
> > -- 
> > 2.51.1
> > 
> > 
> > _______________________________________________
> > Grub-devel mailing list
> > [email protected]
> > https://lists.gnu.org/mailman/listinfo/grub-devel
> 

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