[PATCH] hw/intc: fix heap-buffer-overflow in rxicu_realize()

[Chen Qun]

When 'j = icu->nr_sense – 1', the 'j < icu->nr_sense' condition is true,
then 'j = icu->nr_sense', the'icu->init_sense[j]' has out-of-bounds access.
Maybe this could lead to some security problems.

The asan showed stack:
ERROR: AddressSanitizer: heap-buffer-overflow on address 0x604000004d7d at pc 
0x55852cd26a76 bp 0x7ffe39f26200 sp 0x7ffe39f261f0
READ of size 1 at 0x604000004d7d thread T0
    #0 0x55852cd26a75 in rxicu_realize ../hw/intc/rx_icu.c:311
    #1 0x55852cf075f7 in device_set_realized ../hw/core/qdev.c:886
    #2 0x55852cd4a32f in property_set_bool ../qom/object.c:2251
    #3 0x55852cd4f9bb in object_property_set ../qom/object.c:1398
    #4 0x55852cd54f3f in object_property_set_qobject ../qom/qom-qobject.c:28
    #5 0x55852cd4fc3f in object_property_set_bool ../qom/object.c:1465
    #6 0x55852cbf0b27 in register_icu ../hw/rx/rx62n.c:156
    #7 0x55852cbf12a6 in rx62n_realize ../hw/rx/rx62n.c:261
    #8 0x55852cf075f7 in device_set_realized ../hw/core/qdev.c:886
    #9 0x55852cd4a32f in property_set_bool ../qom/object.c:2251
    #10 0x55852cd4f9bb in object_property_set ../qom/object.c:1398
    #11 0x55852cd54f3f in object_property_set_qobject ../qom/qom-qobject.c:28
    #12 0x55852cd4fc3f in object_property_set_bool ../qom/object.c:1465
    #13 0x55852cbf1a85 in rx_gdbsim_init ../hw/rx/rx-gdbsim.c:109
    #14 0x55852cd22de0 in qemu_init ../softmmu/vl.c:4380
    #15 0x55852ca57088 in main ../softmmu/main.c:49
    #16 0x7feefafa5d42 in __libc_start_main (/lib64/libc.so.6+0x26d42)

Change the 'j < icu->nr_sense' condition place to fix it.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
---
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
---
 hw/intc/rx_icu.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/hw/intc/rx_icu.c b/hw/intc/rx_icu.c
index 94e17a9dea..692a4c78e0 100644
--- a/hw/intc/rx_icu.c
+++ b/hw/intc/rx_icu.c
@@ -308,11 +308,9 @@ static void rxicu_realize(DeviceState *dev, Error **errp)
         return;
     }
     for (i = j = 0; i < NR_IRQS; i++) {
-        if (icu->init_sense[j] == i) {
+        if (j < icu->nr_sense && icu->init_sense[j] == i) {
             icu->src[i].sense = TRG_LEVEL;
-            if (j < icu->nr_sense) {
-                j++;
-            }
+            j++;
         } else {
             icu->src[i].sense = TRG_PEDGE;
         }
-- 
2.27.0