hw/core/qdev-properties: Use qemu_strtol() in set_mac() handler

The MACAddr structure contains an array of uint8_t. Previously
if a value was out of the [0..255] range, it was silently casted
and no input validation was done.
Replace strtol() by qemu_strtol() -- so checkpatch.pl won't
complain if we move this code later -- and return EINVAL if the
input is invalid.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200930164949.1425294-3-philmd@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 343c824da0..080ba319a1 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -1,4 +1,5 @@
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "net/net.h"
 #include "hw/qdev-properties.h"
 #include "qapi/error.h"
@@ -524,7 +525,8 @@ static void set_mac(Object *obj, Visitor *v, const char *name, void *opaque,
     Property *prop = opaque;
     MACAddr *mac = qdev_get_prop_ptr(dev, prop);
     int i, pos;
-    char *str, *p;
+    char *str;
+    const char *p;
 
     if (dev->realized) {
         qdev_prop_set_after_realize(dev, name, errp);
@@ -536,6 +538,8 @@ static void set_mac(Object *obj, Visitor *v, const char *name, void *opaque,
     }
 
     for (i = 0, pos = 0; i < 6; i++, pos += 3) {
+        long val;
+
         if (!qemu_isxdigit(str[pos])) {
             goto inval;
         }
@@ -551,7 +555,10 @@ static void set_mac(Object *obj, Visitor *v, const char *name, void *opaque,
                 goto inval;
             }
         }
-        mac->a[i] = strtol(str+pos, &p, 16);
+        if (qemu_strtol(str + pos, &p, 16, &val) < 0 || val > 0xff) {
+            goto inval;
+        }
+        mac->a[i] = val;
     }
     g_free(str);
     return;