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From: fweimer at redhat dot com (Florian Weimer)
Date: Fri, 05 May 2017 15:18:28 +0200
Subject: [PATCH] sunrpc: xdr_bytes/xdr_string need to free buffer on error [BZ #21461]
[BZ #21461]
Upstream-Status: Backport
CVE: CVE-2017-8804
Signed-off-by: Rajkumar Veer<rveer@mvista.
Index: git/NEWS
===================================================================
--- git.orig/NEWS
+++ git/NEWS
@@ -20,6 +20,9 @@ using `glibc' in the "product" field.
[21624] Unsafe alloca allows local attackers to alias stack and heap (CVE-2017-1000366)
Version 2.24
+* The xdr_bytes and xdr_string routines free the internally allocated buffer
+ if deserialization of the buffer contents fails for any reason.
+
* The minimum Linux kernel version that this version of the GNU C Library
can be used with is 3.2, except on i[4567]86 and x86_64, where Linux
kernel version 2.6.32 or later suffices (on architectures that already
Index: git/sunrpc/Makefile
===================================================================
--- git.orig/sunrpc/Makefile
+++ git/sunrpc/Makefile
@@ -96,9 +96,16 @@ rpcgen-objs = rpc_main.o rpc_hout.o rpc_
extra-objs = $(rpcgen-objs) $(addprefix cross-,$(rpcgen-objs))
others += rpcgen
-tests = tst-xdrmem tst-xdrmem2 test-rpcent
+tests = tst-xdrmem tst-xdrmem2 test-rpcent tst-xdrmem3
xtests := tst-getmyaddr
+tests-special += $(objpfx)mtrace-tst-xdrmem3.out
+generated += mtrace-tst-xdrmem3.out tst-xdrmem3.mtrace
+tst-xdrmem3-ENV = MALLOC_TRACE=$(objpfx)tst-xdrmem3.mtrace
+$(objpfx)mtrace-tst-xdrmem3.out: $(objpfx)tst-xdrmem3.out
+ $(common-objpfx)malloc/mtrace $(objpfx)tst-xdrmem3.mtrace > $@; \
+ $(evaluate-test)
+
ifeq ($(have-thread-library),yes)
xtests += thrsvc
endif
@@ -153,6 +160,7 @@ BUILD_CPPFLAGS += $(sunrpc-CPPFLAGS)
$(objpfx)tst-getmyaddr: $(common-objpfx)linkobj/libc.so
$(objpfx)tst-xdrmem: $(common-objpfx)linkobj/libc.so
$(objpfx)tst-xdrmem2: $(common-objpfx)linkobj/libc.so
+$(objpfx)tst-xdrmem3: $(common-objpfx)linkobj/libc.so
$(objpfx)rpcgen: $(addprefix $(objpfx),$(rpcgen-objs))
Index: git/sunrpc/tst-xdrmem3.c
===================================================================
--- /dev/null
+++ git/sunrpc/tst-xdrmem3.c
@@ -0,0 +1,83 @@
+/* Test xdr_bytes, xdr_string behavior on deserialization failure.
+ Copyright (C) 2017 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 <mcheck.h>
+#include <rpc/rpc.h>
+#include <support/check.h>
+#include <support/support.h>
+
+static int
+do_test (void)
+{
+ mtrace ();
+
+ /* If do_own_buffer, allocate the buffer and pass it to the
+ deserialization routine. Otherwise the routine is requested to
+ allocate the buffer. */
+ for (int do_own_buffer = 0; do_own_buffer < 2; ++do_own_buffer)
+ {
+ /* Length 16 MiB, but only 2 bytes of data in the packet. */
+ unsigned char buf[] = "\x01\x00\x00\x00\xff";
+ XDR xdrs;
+ char *result;
+ unsigned int result_len;
+
+ /* Test xdr_bytes. */
+ xdrmem_create (&xdrs, (char *) buf, sizeof (buf), XDR_DECODE);
+ result_len = 0;
+ if (do_own_buffer)
+ {
+ char *own_buffer = xmalloc (10);
+ result = own_buffer;
+ TEST_VERIFY (!xdr_bytes (&xdrs, &result, &result_len, 10));
+ TEST_VERIFY (result == own_buffer);
+ free (own_buffer);
+ }
+ else
+ {
+ result = NULL;
+ TEST_VERIFY (!xdr_bytes (&xdrs, &result, &result_len, -1));
+ TEST_VERIFY (result == NULL);
+ }
+ TEST_VERIFY (result_len == 16 * 1024 * 1024);
+ xdr_destroy (&xdrs);
+
+ /* Test xdr_string. */
+ xdrmem_create (&xdrs, (char *) buf, sizeof (buf), XDR_DECODE);
+ if (do_own_buffer)
+ {
+ char *own_buffer = xmalloc (10);
+ result = own_buffer;
+ TEST_VERIFY (!xdr_string (&xdrs, &result, 10));
+ TEST_VERIFY (result == own_buffer);
+ free (own_buffer);
+ }
+ else
+ {
+ result = NULL;
+ TEST_VERIFY (!xdr_string (&xdrs, &result, -1));
+ TEST_VERIFY (result == NULL);
+ }
+ xdr_destroy (&xdrs);
+ }
+
+ return 0;
+}
+
+#include <support/test-driver.c>
+
Index: git/sunrpc/xdr.c
===================================================================
--- git.orig/sunrpc/xdr.c
+++ git/sunrpc/xdr.c
@@ -620,14 +620,24 @@ xdr_bytes (XDR *xdrs, char **cpp, u_int
}
if (sp == NULL)
{
- *cpp = sp = (char *) mem_alloc (nodesize);
- }
- if (sp == NULL)
- {
- (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
+ sp = (char *) mem_alloc (nodesize);
+ if (sp == NULL)
+ {
+ (void) __fxprintf (NULL, "%s: %s", __func__,
+ _("out of memory\n"));
+ return FALSE;
+ }
+ }
+ if (!xdr_opaque (xdrs, sp, nodesize))
+ {
+ if (sp != *cpp)
+ /* *cpp was NULL, so this function allocated a new
+ buffer. */
+ free (sp);
return FALSE;
}
- /* fall into ... */
+ *cpp = sp;
+ return TRUE;
case XDR_ENCODE:
return xdr_opaque (xdrs, sp, nodesize);
@@ -781,14 +791,27 @@ xdr_string (XDR *xdrs, char **cpp, u_int
{
case XDR_DECODE:
if (sp == NULL)
- *cpp = sp = (char *) mem_alloc (nodesize);
- if (sp == NULL)
{
- (void) __fxprintf (NULL, "%s: %s", __func__, _("out of memory\n"));
- return FALSE;
+ sp = (char *) mem_alloc (nodesize);
+ if (sp == NULL)
+ {
+ (void) __fxprintf (NULL, "%s: %s", __func__,
+ _("out of memory\n"));
+ return FALSE;
+ }
}
sp[size] = 0;
- /* fall into ... */
+
+ if (!xdr_opaque (xdrs, sp, size))
+ {
+ if (sp != *cpp)
+ /* *cpp was NULL, so this function allocated a new
+ buffer. */
+ free (sp);
+ return FALSE;
+ }
+ *cpp = sp;
+ return TRUE;
case XDR_ENCODE:
return xdr_opaque (xdrs, sp, size);
Index: git/ChangeLog
===================================================================
--- git.orig/ChangeLog
+++ git/ChangeLog
@@ -1,3 +1,16 @@
+2017-05-05 Florian Weimer <fweimer@redhat.com>
+
+ [BZ #21461]
+ * sunrpc/xdr.c (xdr_bytes): Deallocate allocated buffer on error.
+ (xdr_string): Likewise.
+ * sunrpc/Makefile (tests): Add tst-xdrmem3.
+ (tests-special): Add mtrace-tst-xdrmem3.out.
+ (generated): Add mtrace-tst-xdrmem3.out, tst-xdrmem3.mtrace.
+ (tst-xdrmem3-ENV): Set MALLOC_TRACE.
+ (mtrace-tst-xdrmem3.out): Run mtrace.
+ (tst-xdrmem3): Link against full libc.
+ * sunrpc/tst-xdrmem3.c: New file.
+
2017-06-14 Florian Weimer <fweimer@redhat.com>
* sysdeps/i386/i686/multiarch/strcspn-c.c: Add IS_IN (libc) guard.
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