1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 49787e964a0..49aa55577d0 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -195,13 +195,16 @@ static int has_err(unsigned int trap)
 /* deliver_trap() returns true if it could deliver the trap. */
 int deliver_trap(struct lguest *lg, unsigned int num)
 {
-        u32 lo = lg->idt[num].a, hi = lg->idt[num].b;
+        /* Trap numbers are always 8 bit, but we set an impossible trap number
+         * for traps inside the Switcher, so check that here. */
+        if (num >= ARRAY_SIZE(lg->idt))
+                return 0;
 
         /* Early on the Guest hasn't set the IDT entries (or maybe it put a
          * bogus one in): if we fail here, the Guest will be killed. */
-        if (!idt_present(lo, hi))
+        if (!idt_present(lg->idt[num].a, lg->idt[num].b))
                 return 0;
-        set_guest_interrupt(lg, lo, hi, has_err(num));
+        set_guest_interrupt(lg, lg->idt[num].a, lg->idt[num].b, has_err(num));
         return 1;
 }