On Friday, 24 of October 2008, Jesse Barnes wrote: > So who wants to send me a final patch for this? I already did: http://marc.info/?l=linux-kernel&m=122484871717023&w=4 but I can remove the "!output.pointer || " if you prefer. :-) Thanks, Rafael > On Friday, October 24, 2008 7:57 am Moore, Robert wrote: > > Since acpi_evaluate_object doesn't set the pointer value, it may be simply > > random. > > > > >-----Original Message----- > > >From: Rafael J. Wysocki [mailto:rjw@xxxxxxx] > > >Sent: Thursday, October 23, 2008 11:57 PM > > >To: James Bottomley; Jesse Barnes > > >Cc: Moore, Robert; linux-acpi@xxxxxxxxxxxxxxx; linux-kernel; Len Brown > > >Subject: Re: Oops in ACPI with git latest > > > > > >On Friday, 24 of October 2008, James Bottomley wrote: > > >> On Thu, 2008-10-23 at 15:34 -0700, Moore, Robert wrote: > > >> > + if (!output.pointer) > > >> > + return AE_NULL_OBJECT; > > >> > + > > >> > > > >> > This probably won't work. acpi_evaluate_object currently doesn't touch > > > > > >the pointer parameter if there is no return value, it only sets the length > > >to zero. > > > > > >> Actually, it does. > > > > > >Well, this was the only candidate for a NULL pointer dereference, so I'd > > > be surprised if it didn't. :-) > > > > > >> > So, you might try this: > > >> > > > >> > + if (!output.length) > > >> > + return AE_NULL_OBJECT; > > >> > + > > > > > >Still, I'd expect the AML interpreter to return error code in this case. > > > > > >> This also works. > > > > > >Why don't we make it extra safe, then. ;-) > > > > > >--- > > >From: Rafael J. Wysocki <rjw@xxxxxxx> > > >Subject: Prevent acpi_osc_run from using NULL objects > > > > > >Check if the object returned by acpi_evaluate_object() in > > >acpi_run_osc() is not NULL. > > > > > >Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> > > >--- > > > drivers/pci/pci-acpi.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > >Index: linux-2.6/drivers/pci/pci-acpi.c > > >=================================================================== > > >--- linux-2.6.orig/drivers/pci/pci-acpi.c > > >+++ linux-2.6/drivers/pci/pci-acpi.c > > >@@ -83,6 +83,9 @@ static acpi_status acpi_run_osc(acpi_han > > > if (ACPI_FAILURE(status)) > > > return status; > > > > > >+ if (!output.pointer || !output.length) > > >+ return AE_NULL_OBJECT; > > >+ > > > out_obj = output.pointer; > > > if (out_obj->type != ACPI_TYPE_BUFFER) { > > > printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n"); > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
