getaddrinfo.c: Avoid uninitialized pointer access [BZ #32465]

Add valid_decimal_value to check valid decimal value in a string to
avoid uninitialized endp in add_prefixlist and gaiconf_init as reported
by Clang 19:

./getaddrinfo.c:1884:11: error: variable 'endp' is used uninitialized whenever '||' condition is true [-Werror,-Wsometimes-uninitialized]
 1884 |       && (cp == NULL
      |           ^~~~~~~~~~
./getaddrinfo.c:1887:11: note: uninitialized use occurs here
 1887 |       && *endp == '\0'
      |           ^~~~
./getaddrinfo.c:1884:11: note: remove the '||' if its condition is always false
 1884 |       && (cp == NULL
      |           ^~~~~~~~~~
 1885 |           || (bits = strtoul (cp, &endp, 10)) != ULONG_MAX
      |           ~~
./getaddrinfo.c:1875:13: note: initialize the variable 'endp' to silence this warning
 1875 |   char *endp;
      |             ^
      |              = NULL

This fixes BZ #32465.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>

diff --git a/nss/getaddrinfo.c b/nss/getaddrinfo.c
index f8fa9ab7e612cbe65a29620f0482ad843a849922..1cd073535d93375b026396649ec335c7b799bc77 100644 (file)
--- a/nss/getaddrinfo.c
+++ b/nss/getaddrinfo.c
@@ -1865,6 +1865,22 @@ scopecmp (const void *p1, const void *p2)
   return 1;
 }
 
+/* Return true if PTR points to a valid decimal value string and
+   store the value in *VALUE_P.  Otherwise, return false.  */
+
+static bool
+valid_decimal_value (const char *str, unsigned long int *value_p)
+{
+  char *endp;
+  unsigned long int value = strtoul (str, &endp, 10);
+  if (str == endp
+      || *endp != '\0'
+      || (value == ULONG_MAX && errno == ERANGE))
+    return false;
+  *value_p = value;
+  return true;
+}
+
 static bool
 add_prefixlist (struct prefixlist **listp, size_t *lenp, bool *nullbitsp,
                char *val1, char *val2, char **pos)
@@ -1872,7 +1888,6 @@ add_prefixlist (struct prefixlist **listp, size_t *lenp, bool *nullbitsp,
   struct in6_addr prefix;
   unsigned long int bits;
   unsigned long int val;
-  char *endp;
 
   bits = 128;
   __set_errno (0);
@@ -1881,14 +1896,9 @@ add_prefixlist (struct prefixlist **listp, size_t *lenp, bool *nullbitsp,
     *cp++ = '\0';
   *pos = cp;
   if (inet_pton (AF_INET6, val1, &prefix)
-      && (cp == NULL
-         || (bits = strtoul (cp, &endp, 10)) != ULONG_MAX
-         || errno != ERANGE)
-      && *endp == '\0'
+      && (cp == NULL || valid_decimal_value (cp, &bits))
       && bits <= 128
-      && ((val = strtoul (val2, &endp, 10)) != ULONG_MAX
-         || errno != ERANGE)
-      && *endp == '\0'
+      && valid_decimal_value (val2, &val)
       && val <= INT_MAX)
     {
       struct prefixlist *newp = malloc (sizeof (*newp));
@@ -2031,7 +2041,6 @@ gaiconf_init (void)
              struct in6_addr prefix;
              unsigned long int bits;
              unsigned long int val;
-             char *endp;
 
              bits = 32;
              __set_errno (0);
@@ -2042,15 +2051,10 @@ gaiconf_init (void)
                {
                  bits = 128;
                  if (IN6_IS_ADDR_V4MAPPED (&prefix)
-                     && (cp == NULL
-                         || (bits = strtoul (cp, &endp, 10)) != ULONG_MAX
-                         || errno != ERANGE)
-                     && *endp == '\0'
+                     && (cp == NULL || valid_decimal_value (cp, &bits))
                      && bits >= 96
                      && bits <= 128
-                     && ((val = strtoul (val2, &endp, 10)) != ULONG_MAX
-                         || errno != ERANGE)
-                     && *endp == '\0'
+                     && valid_decimal_value (val2, &val)
                      && val <= INT_MAX)
                    {
                      if (!add_scopelist (&scopelist, &nscopelist,
@@ -2064,14 +2068,9 @@ gaiconf_init (void)
                    }
                }
              else if (inet_pton (AF_INET, val1, &prefix.s6_addr32[3])
-                      && (cp == NULL
-                          || (bits = strtoul (cp, &endp, 10)) != ULONG_MAX
-                          || errno != ERANGE)
-                      && *endp == '\0'
+                      && (cp == NULL || valid_decimal_value (cp, &bits))
                       && bits <= 32
-                      && ((val = strtoul (val2, &endp, 10)) != ULONG_MAX
-                          || errno != ERANGE)
-                      && *endp == '\0'
+                      && valid_decimal_value (val2, &val)
                       && val <= INT_MAX)
                {
                  if (!add_scopelist (&scopelist, &nscopelist,