From a3ec4bb7e55956dc633e2248cf76f27d3b9c9c9d Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Thu, 26 Mar 2020 09:56:24 -0400 Subject: [PATCH] acpi: pcihp: fix left shift undefined behavior in acpi_pcihp_eject_slot() 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 Signed-off-by: Igor Mammedov Message-Id: <20200326135624.32464-1-imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- 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; }