Re: [PATCH] m68k/kernel: array out of bound access in process_uboot_commandline

Hangyu Hua
2021-12-27T11:53:11Z

But commandp[len -1] is used to add a zero-terminated. If we don't use
commandp[0]=0 in len == 0,
than commandp will not have a zero-terminated. I think strings may
make some errors beacause of this.

Thanks.

Andreas Schwab <schwab@linux-m68k.org> 于2021年12月27日周一 17:19写道：
>
> On Dez 27 2021, Hangyu Hua wrote:
>
> > diff --git a/arch/m68k/kernel/uboot.c b/arch/m68k/kernel/uboot.c
> > index 928dbd33fc4a..05eca6f653b5 100644
> > --- a/arch/m68k/kernel/uboot.c
> > +++ b/arch/m68k/kernel/uboot.c
> > @@ -101,5 +101,8 @@ __init void process_uboot_commandline(char *commandp, int size)
> > }
> >
> > parse_uboot_commandline(commandp, len);
> > - commandp[len - 1] = 0;
> > + if (len > 0)
> > + commandp[len - 1] = 0;
> > + else
> > + commandp[0] = 0;
>
> If len == 0 then even commandp[0] is OOB.
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
> "And now for something completely different."