Re: [Xen-devel] [PATCH] xen/acpi: off by one in read_acpi_id()

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

On Wed, Mar 28, 2018 at 01:57:20PM +0200, Juergen Gross wrote:
> On 28/03/18 13:47, Dan Carpenter wrote:
> > If acpi_id is == nr_acpi_bits, then we access one element beyond the end
> > of the acpi_psd[] array or we set one bit beyond the end of the bit map
> > when we do __set_bit(acpi_id, acpi_id_cst_present);
> > 
> > Fixes: 59a568029181 ("xen/acpi-processor: C and P-state driver that uploads 
> > said data to hypervisor.")
> > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > 
> > diff --git a/drivers/xen/xen-acpi-processor.c 
> > b/drivers/xen/xen-acpi-processor.c
> > index c80195e8fbd1..d23c9c150199 100644
> > --- a/drivers/xen/xen-acpi-processor.c
> > +++ b/drivers/xen/xen-acpi-processor.c
> > @@ -364,7 +364,7 @@ read_acpi_id(acpi_handle handle, u32 lvl, void 
> > *context, void **rv)
> >     }
> >     /* There are more ACPI Processor objects than in x2APIC or MADT.
> >      * This can happen with incorrect ACPI SSDT declerations. */
> > -   if (acpi_id > nr_acpi_bits) {
> > +   if (acpi_id >= nr_acpi_bits) {
> >             pr_debug("We only have %u, trying to set %u\n",
> >                      nr_acpi_bits, acpi_id);
> 
> Can you please modify this message, too? E.g. something like:
> 
> pr_debug("max acpi id %u, trying to set %u\n",
>          nr_acpi_bits - 1, acpi_id);
> 
> With that:
> 
> Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
> 

Sure, let me resend.

regards,
dan carpenter


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel