[Qemu-devel] [PATCHv3] qdev: Validate hex properties

[Hannes Reinecke]

strtoul(l) might overflow, in which case it'll return '-1' and set
the appropriate error code. So update the calls to strtoul(l) when
parsing hex properties to avoid silent overflows.

Signed-off-by: Hannes Reinecke <h...@suse.de>
---
 hw/core/qdev-properties.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index dc8ae69..4891a01 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -191,6 +191,7 @@ PropertyInfo qdev_prop_uint8 = {
 
 static int parse_hex8(DeviceState *dev, Property *prop, const char *str)
 {
+    unsigned long val;
     uint8_t *ptr = qdev_get_prop_ptr(dev, prop);
     char *end;
 
@@ -198,11 +199,18 @@ static int parse_hex8(DeviceState *dev, Property *prop, 
const char *str)
         return -EINVAL;
     }
 
-    *ptr = strtoul(str, &end, 16);
+    errno = 0;
+    val = strtoul(str, &end, 16);
+    if (errno) {
+        return -errno;
+    }
+    if (val > 255) {
+        return -ERANGE;
+    }
     if ((*end != '\0') || (end == str)) {
         return -EINVAL;
     }
-
+    *ptr = val;
     return 0;
 }
 
@@ -329,7 +337,11 @@ static int parse_hex32(DeviceState *dev, Property *prop, 
const char *str)
         return -EINVAL;
     }
 
+    errno = 0;
     *ptr = strtoul(str, &end, 16);
+    if (errno) {
+        return -errno;
+    }
     if ((*end != '\0') || (end == str)) {
         return -EINVAL;
     }
@@ -396,7 +408,11 @@ static int parse_hex64(DeviceState *dev, Property *prop, 
const char *str)
         return -EINVAL;
     }
 
+    errno = 0;
     *ptr = strtoull(str, &end, 16);
+    if (errno) {
+        return -errno;
+    }
     if ((*end != '\0') || (end == str)) {
         return -EINVAL;
     }
-- 
1.8.1.4