Avoid access beyond memory bounds in pthread_attr_getaffinity_np

Resolves BZ #15618.

pthread_attr_getaffinity_np may write beyond bounds of the input
cpuset buffer if the size of the input buffer is smaller than the
buffer present in the input pthread attributes.  Fix is to copy to the
extent of the minimum of the source and the destination.

diff --git a/NEWS b/NEWS
index 42dfecea985bbef651482e6663f20f910acd92a6..afbcacc7ef10ca20d3eb634baa5bd275e0d32017 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -20,7 +20,7 @@ Version 2.18
   15380, 15381, 15394, 15395, 15405, 15406, 15409, 15416, 15418, 15419,
   15423, 15424, 15426, 15429, 15431, 15432, 15441, 15442, 15448, 15465,
   15480, 15485, 15488, 15490, 15493, 15497, 15506, 15529, 15536, 15553,
-  15577, 15583.
+  15577, 15583, 15618.
 
 * CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
   #15078).

diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index 8fb473f3eac59c30048afdd0ac54c381322455b8..64b674c678fd3b3cfe699df34bd4ea64fc3c15c4 100644 (file)
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,3 +1,13 @@
+2013-06-13  Siddhesh Poyarekar  <siddhesh@redhat.com>
+           Carlos O'Donell  <carlos@redhat.com>
+
+       [BZ #15618]
+       * tst-pthread-attr-affinity: New test case.
+       * Makefile (tests): Add it.
+       * sysdeps/unix/sysv/linux/pthread_attr_getaffinity.c
+       (__pthread_attr_getaffinity_new): Copy minimum of source and
+       destination sizes to avoid a buffer overrun.
+
 2013-06-10  Carlos O'Donell  <carlos@redhat.com>
 
        * sysdeps/unix/sysv/linux/i386/lowlevellock.h

diff --git a/nptl/Makefile b/nptl/Makefile
index 7fa991b25186ec21958fb89c6b491cb6b703ef02..4788bd8035cc79fb025c280fcfa86f00b87458cf 100644 (file)
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -252,6 +252,7 @@ tests = tst-typesizes \
        tst-exit1 tst-exit2 tst-exit3 \
        tst-stdio1 tst-stdio2 \
        tst-stack1 tst-stack2 tst-stack3 tst-pthread-getattr \
+       tst-pthread-attr-affinity \
        tst-unload \
        tst-dlsym1 \
        tst-sysconf \

diff --git a/nptl/sysdeps/unix/sysv/linux/pthread_attr_getaffinity.c b/nptl/sysdeps/unix/sysv/linux/pthread_attr_getaffinity.c
index 00bb29b3f59f625233984b0270d125156c14645e..2a60f8e19f02f06f7817229916bf821c56e3382a 100644 (file)
--- a/nptl/sysdeps/unix/sysv/linux/pthread_attr_getaffinity.c
+++ b/nptl/sysdeps/unix/sysv/linux/pthread_attr_getaffinity.c
@@ -42,7 +42,12 @@ __pthread_attr_getaffinity_new (const pthread_attr_t *attr, size_t cpusetsize,
        if (((char *) iattr->cpuset)[cnt] != 0)
          return EINVAL;
 
-      void *p = mempcpy (cpuset, iattr->cpuset, iattr->cpusetsize);
+      /* Copy over the cpuset from the thread attribute object.  Limit the copy
+        to the minimum of the source and destination sizes to prevent a buffer
+        overrun.  If the destination is larger, fill the remaining space with
+        zeroes.  */
+      void *p = mempcpy (cpuset, iattr->cpuset,
+                        MIN (iattr->cpusetsize, cpusetsize));
       if (cpusetsize > iattr->cpusetsize)
        memset (p, '\0', cpusetsize - iattr->cpusetsize);
     }

diff --git a/nptl/tst-pthread-attr-affinity.c b/nptl/tst-pthread-attr-affinity.c
new file mode 100644 (file)
index 0000000..eab0820
--- /dev/null
+++ b/nptl/tst-pthread-attr-affinity.c
@@ -0,0 +1,63 @@
+/* Make sure that pthread_attr_getaffinity_np does not crash when the input
+   cpuset size is smaller than that in the attribute structure.
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <sched.h>
+#include <errno.h>
+#include <sys/param.h>
+
+
+#define RETURN_IF_FAIL(f, ...) \
+  ({                                                                         \
+    int ret = f (__VA_ARGS__);                                               \
+    if (ret != 0)                                                            \
+      {                                                                              \
+       printf ("%s:%d: %s returned %d (errno = %d)\n", __FILE__, __LINE__,   \
+               #f, ret, errno);                                              \
+       return ret;                                                           \
+      }                                                                              \
+  })
+
+static int
+do_test (void)
+{
+  for (int i = 0; i < 10; i++)
+    {
+      pthread_attr_t attr;
+      cpu_set_t *cpuset = CPU_ALLOC (512);
+      size_t cpusetsize = CPU_ALLOC_SIZE (512);
+      CPU_ZERO_S (cpusetsize, cpuset);
+
+      RETURN_IF_FAIL (pthread_attr_init, &attr);
+      RETURN_IF_FAIL (pthread_attr_setaffinity_np, &attr, cpusetsize, cpuset);
+      CPU_FREE (cpuset);
+
+      cpuset = CPU_ALLOC (1);
+      cpusetsize = CPU_ALLOC_SIZE (1);
+      RETURN_IF_FAIL (pthread_attr_getaffinity_np, &attr, cpusetsize, cpuset);
+      CPU_FREE (cpuset);
+    }
+  return 0;
+}
+
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"