Fix crash when system has no ipv6 address [BZ #17125]

Here's an updated patch to fix the crash in bug-ga2 when the system
has no configured ipv6 address.  I have taken a different approach of
using libc_freeres_fn instead of the libc_freeres_ptr since the former
gives better control over what is freed; we need that since cache may
or may not be allocated using malloc.

Verified that bug-ga2 works correctly in both cases and does not have
memory leaks in either of them.

diff --git a/ChangeLog b/ChangeLog
index f5b5599..72e9cf9 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2014-07-10  Siddhesh Poyarekar  <siddhesh@redhat.com>
 
+       [BZ #17125]
+       * sysdeps/unix/sysv/linux/check_pf.c (cache): Don't use
+       libc_freeres_ptr.
+       (freecache): New function to free CACHE on exit.
+
        * sunrpc/xdr.c (xdr_string): Add comment about SIZE
        initialization.
 

diff --git a/NEWS b/NEWS
index f4c501c..3ef9162 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -21,7 +21,7 @@ Version 2.20
   16882, 16885, 16888, 16890, 16912, 16915, 16916, 16917, 16918, 16922,
   16927, 16928, 16932, 16943, 16958, 16965, 16966, 16967, 16977, 16978,
   16984, 16990, 16996, 17009, 17022, 17031, 17042, 17048, 17050, 17058,
-  17061, 17062, 17069, 17075, 17079, 17084, 17086, 17092, 17097.
+  17061, 17062, 17069, 17075, 17079, 17084, 17086, 17092, 17097, 17125.
 
 * Optimized strchr implementation for AArch64.  Contributed by ARM Ltd.
 

diff --git a/sysdeps/unix/sysv/linux/check_pf.c b/sysdeps/unix/sysv/linux/check_pf.c
index 1bc1def..c7fd9b0 100644 (file)
--- a/sysdeps/unix/sysv/linux/check_pf.c
+++ b/sysdeps/unix/sysv/linux/check_pf.c
@@ -61,7 +61,7 @@ static struct cached_data noai6ai_cached =
     .in6ailen = 0
   };
 
-libc_freeres_ptr (static struct cached_data *cache);
+static struct cached_data *cache;
 __libc_lock_define_initialized (static, lock);
 
 
@@ -401,6 +401,12 @@ __check_pf (bool *seen_ipv4, bool *seen_ipv6,
   *seen_ipv6 = true;
 }
 
+/* Free the cache if it has been allocated.  */
+libc_freeres_fn (freecache)
+{
+  if (cache)
+    __free_in6ai (cache->in6ai);
+}
 
 void
 __free_in6ai (struct in6addrinfo *ai)