[PATCH -next] x86/xen: Fix read buffer overflow

From: YueHaibing
Date: Tue Dec 18 2018 - 03:22:14 EST


Fix smatch warning:

arch/x86/xen/enlighten_pv.c:649 get_trap_addr() error:
buffer overflow 'early_idt_handler_array' 32 <= 32

Fixes: 42b3a4cb5609 ("x86/xen: Support early interrupts in xen pv guests")
Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
---
arch/x86/xen/enlighten_pv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 2f6787f..81f200d 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -646,7 +646,7 @@ static bool __ref get_trap_addr(void **addr, unsigned int ist)

if (nr == ARRAY_SIZE(trap_array) &&
*addr >= (void *)early_idt_handler_array[0] &&
- *addr < (void *)early_idt_handler_array[NUM_EXCEPTION_VECTORS]) {
+ *addr < (void *)early_idt_handler_array[NUM_EXCEPTION_VECTORS - 1]) {
nr = (*addr - (void *)early_idt_handler_array[0]) /
EARLY_IDT_HANDLER_SIZE;
*addr = (void *)xen_early_idt_handler_array[nr];
--
2.7.0