| Message ID | 20200326135624.32464-1-imammedo@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | acpi: pcihp: fix left shift undefined behavior in acpi_pcihp_eject_slot() | expand |
On Thu, Mar 26, 2020 at 09:56:24AM -0400, Igor Mammedov wrote: > Coverity spots subj in following guest triggered code path > pci_write(, data = 0) -> acpi_pcihp_eject_slot(,slots = 0) > uinst32_t slot = ctz32(slots) > ... > ... = ~(1U << slot) > where 'slot' value is 32 in case 'slots' bitmap is empty. > 'slots' is a bitmap and empty one shouldn't do anything > so return early doing nothing if resulted slot value is > not valid (i.e. not in 0-31 range) > > Reported-by: Peter Maydell <peter.maydell@linaro.org> > Signed-off-by: Igor Mammedov <imammedo@redhat.com> tagged, thanks! > --- > hw/acpi/pcihp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c > index 4dcef372bf..0dc963e983 100644 > --- a/hw/acpi/pcihp.c > +++ b/hw/acpi/pcihp.c > @@ -154,7 +154,7 @@ static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slo > > trace_acpi_pci_eject_slot(bsel, slot); > > - if (!bus) { > + if (!bus || slot > 31) { > return; > } > > -- > 2.18.1
diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c index 4dcef372bf..0dc963e983 100644 --- a/hw/acpi/pcihp.c +++ b/hw/acpi/pcihp.c @@ -154,7 +154,7 @@ static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slo trace_acpi_pci_eject_slot(bsel, slot); - if (!bus) { + if (!bus || slot > 31) { return; }
Coverity spots subj in following guest triggered code path pci_write(, data = 0) -> acpi_pcihp_eject_slot(,slots = 0) uinst32_t slot = ctz32(slots) ... ... = ~(1U << slot) where 'slot' value is 32 in case 'slots' bitmap is empty. 'slots' is a bitmap and empty one shouldn't do anything so return early doing nothing if resulted slot value is not valid (i.e. not in 0-31 range) Reported-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Igor Mammedov <imammedo@redhat.com> --- hw/acpi/pcihp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)