Adjust pointers to triplets in netgroup query data (BZ #16474)

The _nss_*_getnetgrent_r query populates the netgroup results in the
allocated buffer and then sets the result triplet to point to strings
in the buffer.  This is a problem when the buffer is reallocated since
the pointers to the triplet strings are no longer valid.  The pointers
need to be adjusted so that they now point to strings in the
reallocated buffer.

diff --git a/ChangeLog b/ChangeLog
index 0f4453e..1d19695 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-01-24  Siddhesh Poyarekar  <siddhesh@redhat.com>
+
+       [BZ #16474]
+       * nscd/netgroupcache.c (addgetnetgrentX): Adjust triplet
+       string pointers after reallocation.
+
 2014-01-24  Kaz Kojima  <kkojima@rr.iij4u.or.jp>
 
        * sysdeps/unix/sysv/linux/sh/sys/ucontext.h: Use __SH4__ and

diff --git a/NEWS b/NEWS
index f4f22a8..5601403 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -25,7 +25,7 @@ Version 2.19
   16151, 16153, 16167, 16169, 16172, 16195, 16214, 16245, 16271, 16274,
   16283, 16289, 16293, 16314, 16316, 16330, 16337, 16338, 16356, 16365,
   16366, 16369, 16372, 16375, 16379, 16384, 16385, 16386, 16387, 16390,
-  16394, 16400, 16407, 16408, 16414, 16430, 16431, 16453.
+  16394, 16400, 16407, 16408, 16414, 16430, 16431, 16453, 16474.
 
 * Slovenian translations for glibc messages have been contributed by the
   Translation Project's Slovenian team of translators.

diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index 58234b1..924567c 100644 (file)
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -241,7 +241,17 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
                                if (buflen - req->key_len - bufused < needed)
                                  {
                                    buflen += MAX (buflen, 2 * needed);
-                                   buffer = xrealloc (buffer, buflen);
+                                   char *newbuf = xrealloc (buffer, buflen);
+                                   /* Adjust the pointers in the new
+                                      buffer.  */
+                                   nhost = (nhost ? newbuf + (nhost - buffer)
+                                            : NULL);
+                                   nuser = (nuser ? newbuf + (nuser - buffer)
+                                            : NULL);
+                                   ndomain = (ndomain
+                                              ? newbuf + (ndomain - buffer)
+                                              : NULL);
+                                   buffer = newbuf;
                                  }
 
                                nhost = memcpy (buffer + bufused,