Fix _nl_find_msg malloc failure case, and callers.

This patch fixes two issues, and perhaps should be two distinct commits,
but I present it here as one for the sake of completeness.

Commit 006dd86111c44572dbd3b26e9c63dd0f834d7762 fails to check malloc's
return in intl/dcigettext.c (_nl_find_msg):
~~~
      freemem_size = INITIAL_BLOCK_SIZE;
      newmem = (transmem_block_t *) malloc (freemem_size);
...
      newmem->next = transmem_list;
      transmem_list = newmem;
~~~
If malloc fails then newmem is NULL then newmem->next results in a
fault.

The fix is easy enough, check for newmem != NULL, and fall through to
the error condition below which returns (char *) -1 e.g. resource error.

The problem is that returning (char *) -1  will break all sorts of other
code, so while what we did is correct, the real failure case fix is
slightly broader.

There are 4 other places where _nl_find_msg is called, one is OK, the
other three are fixed to handle -1 error return value.

No regressions on x86-64 or x86.

However, no regressions isn't really a useful metric for this code.

The change was tested as documented here:
http://sourceware.org/glibc/wiki/Testing/WhiteBox
using SystemTap for fault injection to simulate malloc failure.

---

2013-05-03  Carlos O'Donell  <carlos at redhat.com>

	[BZ #15441]
	* intl/dcigettext.c (DCIGETTEXT): Skip translating if _nl_find_msg
	returns -1.
	(_nl_find_msg): Return -1 if recursive call returned -1. If newmem is
	null return -1.
	* intl/loadmsgcat.c (_nl_load_domain): If _nl_find_msg returns -1 abort
	loading the domain.

diff --git a/ChangeLog b/ChangeLog
index 46a36ce..49d3c36 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2013-05-03  Carlos O'Donell  <carlos at redhat.com>
+
+       [BZ #15441]
+       * intl/dcigettext.c (DCIGETTEXT): Skip translating if _nl_find_msg
+       returns -1.
+       (_nl_find_msg): Return -1 if recursive call returned -1. If newmem is
+       null return -1.
+       * intl/loadmsgcat.c (_nl_load_domain): If _nl_find_msg returns -1 abort
+       loading the domain.
+
 2013-05-22  Joseph Myers  <joseph@codesourcery.com>
 
        * math/gen-libm-test.pl (parse_args): Do not include expected

diff --git a/NEWS b/NEWS
index 970c53b..152e7a4 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -17,8 +17,8 @@ Version 2.18
   15085, 15086, 15160, 15214, 15221, 15232, 15234, 15283, 15285, 15287,
   15304, 15305, 15307, 15309, 15327, 15330, 15335, 15336, 15337, 15339,
   15342, 15346, 15359, 15361, 15366, 15380, 15394, 15395, 15405, 15406,
-  15409, 15416, 15418, 15419, 15423, 15424, 15426, 15429, 15442, 15448,
-  15480, 15485, 15488, 15490, 15493, 15497, 15506.
+  15409, 15416, 15418, 15419, 15423, 15424, 15426, 15429, 15441, 15442,
+  15448, 15480, 15485, 15488, 15490, 15493, 15497, 15506.
 
 * CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
   #15078).

diff --git a/intl/dcigettext.c b/intl/dcigettext.c
index 110307b..f4aa215 100644 (file)
--- a/intl/dcigettext.c
+++ b/intl/dcigettext.c
@@ -638,6 +638,11 @@ DCIGETTEXT (domainname, msgid1, msgid2, plural, n, category)
                  retval = _nl_find_msg (domain->successor[cnt], binding,
                                         msgid1, 1, &retlen);
 
+                 /* Resource problems are not fatal, instead we return no
+                    translation.  */
+                 if (__builtin_expect (retval == (char *) -1, 0))
+                   goto no_translation;
+
                  if (retval != NULL)
                    {
                      domain = domain->successor[cnt];
@@ -941,6 +946,11 @@ _nl_find_msg (domain_file, domainbinding, msgid, convert, lengthp)
            nullentry =
              _nl_find_msg (domain_file, domainbinding, "", 0, &nullentrylen);
 
+           /* Resource problems are fatal.  If we continue onwards we will
+              only attempt to calloc a new conv_tab and fail later.  */
+           if (__builtin_expect (nullentry == (char *) -1, 0))
+             return (char *) -1;
+
            if (nullentry != NULL)
              {
                const char *charsetstr;
@@ -1170,10 +1180,14 @@ _nl_find_msg (domain_file, domainbinding, msgid, convert, lengthp)
                      freemem_size = INITIAL_BLOCK_SIZE;
                      newmem = (transmem_block_t *) malloc (freemem_size);
 # ifdef _LIBC
-                     /* Add the block to the list of blocks we have to free
-                        at some point.  */
-                     newmem->next = transmem_list;
-                     transmem_list = newmem;
+                     if (newmem != NULL)
+                       {
+                         /* Add the block to the list of blocks we have to free
+                            at some point.  */
+                         newmem->next = transmem_list;
+                         transmem_list = newmem;
+                       }
+                     /* Fall through and return -1.  */
 # endif
                    }
                  if (__builtin_expect (newmem == NULL, 0))

diff --git a/intl/loadmsgcat.c b/intl/loadmsgcat.c
index e4b7b38..ac90ed1 100644 (file)
--- a/intl/loadmsgcat.c
+++ b/intl/loadmsgcat.c
@@ -1237,7 +1237,7 @@ _nl_load_domain (domain_file, domainbinding)
     default:
       /* This is an invalid revision.  */
     invalid:
-      /* This is an invalid .mo file.  */
+      /* This is an invalid .mo file or we ran out of resources.  */
       free (domain->malloced);
 #ifdef HAVE_MMAP
       if (use_mmap)
@@ -1257,6 +1257,11 @@ _nl_load_domain (domain_file, domainbinding)
 
   /* Get the header entry and look for a plural specification.  */
   nullentry = _nl_find_msg (domain_file, domainbinding, "", 0, &nullentrylen);
+  if (__builtin_expect (nullentry == (char *) -1, 0))
+    {
+      __libc_rwlock_fini (domain->conversions_lock);
+      goto invalid;
+    }
   EXTRACT_PLURAL_EXPRESSION (nullentry, &domain->plural, &domain->nplurals);
 
  out: