uat: tighten up dec/hex uat field validity checking

Specifically:
- Use the proper code for testing strtol() result;
- Also: Values greater than 32-bits treated as an error
   (on LP64 architectures);

Change-Id: I56e8e734fbb9a22dbd9ed4112e24327ffd7ee3c0
Reviewed-on: https://code.wireshark.org/review/5394
Reviewed-by: Bill Meier <wmeier@newsguy.com>
Petri-Dish: Bill Meier <wmeier@newsguy.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>

1 files changed, 22 insertions, 15 deletions

diff --git a/epan/uat.c b/epan/uat.c
index 076ac48e5a..824e64d5a2 100644
--- a/epan/uat.c
+++ b/epan/uat.c
@@ -497,34 +497,41 @@ gboolean uat_fld_chk_proto(void* u1 _U_, const char* strptr, guint len, const vo
     }
 }
 
-gboolean uat_fld_chk_num_dec(void* u1 _U_, const char* strptr, guint len, const void* u2 _U_, const void* u3 _U_, const char** err) {
+static gboolean uat_fld_chk_num(int base, const char* strptr, guint len, const char** err) {
     if (len > 0) {
         char* str = ep_strndup(strptr,len);
-        long i = strtol(str,&str,10);
+        char* strn;
+        long i;
+
+        errno = 0;
+        i = strtol(str,&strn,base);
 
-        if ( ( i == 0) && (errno == ERANGE || errno == EINVAL) ) {
+        if (((i == G_MAXLONG || i == G_MINLONG) && errno == ERANGE)
+            || (errno != 0 && i == 0)) {
             *err = g_strerror(errno);
             return FALSE;
         }
+        if ((*strn != '\0') && (*strn != ' ')) {
+            *err = "Invalid value";
+            return FALSE;
+        }
+        /* Allow only 32bit values */
+        if ((sizeof(long) > 4) && ((i < G_MININT) || (i > G_MAXINT))) {
+            *err = "Value too large";
+            return FALSE;
+        }
     }
 
     *err = NULL;
     return TRUE;
 }
 
-gboolean uat_fld_chk_num_hex(void* u1 _U_, const char* strptr, guint len, const void* u2 _U_, const void* u3 _U_, const char** err) {
-    if (len > 0) {
-        char* str = ep_strndup(strptr,len);
-        long i = strtol(str,&str,16);
-
-        if ( ( i == 0) && (errno == ERANGE || errno == EINVAL) ) {
-            *err = g_strerror(errno);
-            return FALSE;
-        }
-    }
+gboolean uat_fld_chk_num_dec(void* u1 _U_, const char* strptr, guint len, const void* u2 _U_, const void* u3 _U_, const char** err) {
+    return uat_fld_chk_num(10, strptr, len, err);
+}
 
-    *err = NULL;
-    return TRUE;
+gboolean uat_fld_chk_num_hex(void* u1 _U_, const char* strptr, guint len, const void* u2 _U_, const void* u3 _U_, const char** err) {
+    return uat_fld_chk_num(16, strptr, len, err);
 }
 
 gboolean uat_fld_chk_enum(void* u1 _U_, const char* strptr, guint len, const void* v, const void* u3 _U_, const char** err) {