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[PATCH] ld.so: Add original DSO name if overridden by audit module [BZ #18251]


This is basically the patch from the bug, with whitespace changes
removed, recommended headers in the test cases, and unreachable code
removed from the test cases.

I verified that the new tests are valid (they fail before the change to
dl-load.c, and succeed afterwards).  But I'm not familiar with ld.so, so
I don't know if the patch is actually correct.  I just want to move this
forward.

Thanks,
Florian
2015-11-04  Ulrich Drepper  <drepper@gmail.com>

	* elf/dl-load.c (_dl_map_object_from_fd): Add additional parameter
	for original name of the DSO.  Add it to the name list of the DSO
	if it is actually given.
	(_dl_map_object): Keep track of whether an audit module rewrote
	the file name.  If yes, pass the original name to
	_dl_map_object_from_fd in a new parameter, otherwise NULL.  When
	debugging is enabled, log the change of the file name.
	* sysdeps/mach/hur/dl-sysdep.c: Adjust commented-out call to
	_dl_map_object_from_fd.
	* elf/Makefile: Build and run tst-audit11 and tst-audit12.
	* elf/tst-audit11.c: New file
	* elf/tst-auditmod11.c: New file.
	* elf/tst-audit11mod1.c: New file.
	* elf/tst-audit11mod2.c: New file.
	* elf/tst-audit11mod2.map: New file.
	* elf/tst-audit12.c: New file
	* elf/tst-auditmod12.c: New file.
	* elf/tst-audit12mod1.c: New file.
	* elf/tst-audit12mod2.c: New file.
	* elf/tst-audit12mod2.map: New file.
	* elf/tst-audit12mod3.c: New file.

diff --git a/elf/Makefile b/elf/Makefile
index 546c8eb..76985cc 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -149,7 +149,7 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
 	 tst-nodelete) \
 	 tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \
 	 tst-ptrguard1 tst-tlsalign tst-tlsalign-extern tst-nodelete-opened \
-	 tst-nodelete2
+	 tst-nodelete2 tst-audit11 tst-audit12
 #	 reldep9
 ifeq ($(build-hardcoded-path-in-tests),yes)
 tests += tst-dlopen-aout
@@ -219,7 +219,9 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
 		tst-initorder2d \
 		tst-relsort1mod1 tst-relsort1mod2 tst-array2dep \
 		tst-array5dep tst-null-argv-lib \
-		tst-tlsalign-lib tst-nodelete-opened-lib tst-nodelete2mod
+		tst-tlsalign-lib tst-nodelete-opened-lib tst-nodelete2mod \
+		tst-audit11mod1 tst-audit11mod2 tst-auditmod11 \
+		tst-audit12mod1 tst-audit12mod2 tst-audit12mod3 tst-auditmod12
 ifeq (yes,$(have-protected-data))
 modules-names += tst-protected1moda tst-protected1modb
 tests += tst-protected1a tst-protected1b
@@ -1220,3 +1222,15 @@ $(objpfx)tst-unused-dep.out: $(objpfx)testobj1.so
 $(objpfx)tst-unused-dep-cmp.out: $(objpfx)tst-unused-dep.out
 	cmp $< /dev/null > $@; \
 	$(evaluate-test)
+
+$(objpfx)tst-audit11.out: $(objpfx)tst-auditmod11.so $(objpfx)tst-audit11mod1.so
+$(objpfx)tst-audit11: $(libdl)
+tst-audit11-ENV = LD_AUDIT=$(objpfx)tst-auditmod11.so
+$(objpfx)tst-audit11mod1.so: $(objpfx)tst-audit11mod2.so
+LDFLAGS-tst-audit11mod2.so = -Wl,--version-script=tst-audit11mod2.map,-soname,tst-audit11mod2.so
+
+$(objpfx)tst-audit12.out: $(objpfx)tst-auditmod12.so $(objpfx)tst-audit12mod1.so $(objpfx)tst-audit12mod3.so
+$(objpfx)tst-audit12: $(libdl)
+tst-audit12-ENV = LD_AUDIT=$(objpfx)tst-auditmod12.so
+$(objpfx)tst-audit12mod1.so: $(objpfx)tst-audit12mod2.so
+LDFLAGS-tst-audit12mod2.so = -Wl,--version-script=tst-audit12mod2.map
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 993a419..c5e948e 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -863,9 +863,10 @@ lose (int code, int fd, const char *name, char *realname, struct link_map *l,
 static
 #endif
 struct link_map *
-_dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
-			char *realname, struct link_map *loader, int l_type,
-			int mode, void **stack_endp, Lmid_t nsid)
+_dl_map_object_from_fd (const char *name, const char *origname, int fd,
+			struct filebuf *fbp, char *realname,
+			struct link_map *loader, int l_type, int mode,
+			void **stack_endp, Lmid_t nsid)
 {
   struct link_map *l = NULL;
   const ElfW(Ehdr) *header;
@@ -1391,6 +1392,17 @@ cannot enable executable stack as shared object requires");
   /* Finally the file information.  */
   l->l_file_id = id;
 
+#ifdef SHARED
+  /* When auditing is used the recorded names might not include the
+     name by which the DSO is actually known.  Add that as well.  */
+  if (__glibc_unlikely (origname != NULL))
+    add_name_to_object (l, origname);
+#else
+  /* Audit modules only exist when linking is dynamic so ORIGNAME
+     cannot be non-NULL.  */
+  assert (origname == NULL);
+#endif
+
   /* When we profile the SONAME might be needed for something else but
      loading.  Add it right away.  */
   if (__glibc_unlikely (GLRO(dl_profile) != NULL)
@@ -1904,6 +1916,7 @@ _dl_map_object (struct link_map *loader, const char *name,
 		int type, int trace_mode, int mode, Lmid_t nsid)
 {
   int fd;
+  const char *origname = NULL;
   char *realname;
   char *name_copy;
   struct link_map *l;
@@ -1961,6 +1974,7 @@ _dl_map_object (struct link_map *loader, const char *name,
 	{
 	  if (afct->objsearch != NULL)
 	    {
+	      const char *before = name;
 	      name = afct->objsearch (name, &loader->l_audit[cnt].cookie,
 				      LA_SER_ORIG);
 	      if (name == NULL)
@@ -1969,6 +1983,15 @@ _dl_map_object (struct link_map *loader, const char *name,
 		  fd = -1;
 		  goto no_file;
 		}
+	      if (before != name && strcmp (before, name) != 0)
+		{
+		  if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
+		    _dl_debug_printf ("audit changed filename %s -> %s\n",
+				      before, name);
+
+		  if (origname == NULL)
+		    origname = before;
+		}
 	    }
 
 	  afct = afct->next;
@@ -2183,8 +2206,8 @@ _dl_map_object (struct link_map *loader, const char *name,
     }
 
   void *stack_end = __libc_stack_end;
-  return _dl_map_object_from_fd (name, fd, &fb, realname, loader, type, mode,
-				 &stack_end, nsid);
+  return _dl_map_object_from_fd (name, origname, fd, &fb, realname, loader,
+				 type, mode, &stack_end, nsid);
 }
 
 struct add_path_state
diff --git a/elf/tst-audit11.c b/elf/tst-audit11.c
new file mode 100644
index 0000000..15a44f9
--- /dev/null
+++ b/elf/tst-audit11.c
@@ -0,0 +1,36 @@
+/* Test version symbol binding can find a DSO replaced by la_objsearch.
+   Copyright (C) 2015 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 <dlfcn.h>
+#include <stdio.h>
+
+int
+do_test (void)
+{
+  puts ("Start");
+  if (dlopen ("$ORIGIN/tst-audit11mod1.so", RTLD_LAZY) == NULL)
+    {
+      printf ("module not loaded: %s\n", dlerror ());
+      return 1;
+    }
+  puts ("OK");
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/elf/tst-audit11mod1.c b/elf/tst-audit11mod1.c
new file mode 100644
index 0000000..32df01f
--- /dev/null
+++ b/elf/tst-audit11mod1.c
@@ -0,0 +1,24 @@
+/* DSO directly opened by tst-audit11.
+   Copyright (C) 2015 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/>.  */
+
+extern int f2 (void);
+int
+f1 (void)
+{
+  return f2 ();
+}
diff --git a/elf/tst-audit11mod2.c b/elf/tst-audit11mod2.c
new file mode 100644
index 0000000..211456f
--- /dev/null
+++ b/elf/tst-audit11mod2.c
@@ -0,0 +1,23 @@
+/* DSO indirectly opened by tst-audit11, with symbol versioning.
+   Copyright (C) 2015 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/>.  */
+
+int
+f2 (void)
+{
+  return 42;
+}
diff --git a/elf/tst-audit11mod2.map b/elf/tst-audit11mod2.map
new file mode 100644
index 0000000..76d4d5b
--- /dev/null
+++ b/elf/tst-audit11mod2.map
@@ -0,0 +1,22 @@
+/* Symbol versioning for the DSO indirectly opened by tst-audit11.
+   Copyright (C) 2015 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/>.  */
+
+V1 {
+  global: f2;
+  local: *;
+};
diff --git a/elf/tst-audit12.c b/elf/tst-audit12.c
new file mode 100644
index 0000000..cd026bd
--- /dev/null
+++ b/elf/tst-audit12.c
@@ -0,0 +1,49 @@
+/* Test that symbol is bound to a DSO replaced by la_objsearch.
+   Copyright (C) 2015 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 <dlfcn.h>
+#include <stdio.h>
+
+int
+do_test (void)
+{
+  puts ("Start");
+  void *h = dlopen ("$ORIGIN/tst-audit12mod1.so", RTLD_LAZY);
+  if (h == NULL)
+    {
+      printf ("module not loaded: %s\n", dlerror ());
+      return 1;
+    }
+  int (*fp) (void) = (int (*) (void)) dlsym (h, "f1");
+  if (fp == NULL)
+    {
+      printf ("function f1 not found: %s\n", dlerror ());
+      return 1;
+    }
+  int res = fp ();
+  if (res != 43)
+    {
+      puts ("incorrect function f2 called");
+      return 1;
+    }
+  printf ("%d is OK\n", res);
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/elf/tst-audit12mod1.c b/elf/tst-audit12mod1.c
new file mode 100644
index 0000000..9ad73b6
--- /dev/null
+++ b/elf/tst-audit12mod1.c
@@ -0,0 +1,24 @@
+/* DSO directly opened by tst-audit12.
+   Copyright (C) 2015 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/>.  */
+
+extern int f2 (void);
+int
+f1 (void)
+{
+  return f2 ();
+}
diff --git a/elf/tst-audit12mod2.c b/elf/tst-audit12mod2.c
new file mode 100644
index 0000000..de48b6a
--- /dev/null
+++ b/elf/tst-audit12mod2.c
@@ -0,0 +1,23 @@
+/* Replaced DSO referenced by tst-audit12mod1.so, for tst-audit12.
+   Copyright (C) 2015 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/>.  */
+
+int
+f2 (void)
+{
+  return 42;
+}
diff --git a/elf/tst-audit12mod2.map b/elf/tst-audit12mod2.map
new file mode 100644
index 0000000..1030ac6
--- /dev/null
+++ b/elf/tst-audit12mod2.map
@@ -0,0 +1,22 @@
+/* Symbol versioning for tst-audit12mod2.so used by tst-audit12.
+   Copyright (C) 2015 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/>.  */
+
+V1 {
+  global: f2;
+  local: *;
+};
diff --git a/elf/tst-audit12mod3.c b/elf/tst-audit12mod3.c
new file mode 100644
index 0000000..e4e9d4b
--- /dev/null
+++ b/elf/tst-audit12mod3.c
@@ -0,0 +1,23 @@
+/* Replacement DSO loaded by the audit module, for tst-audit12.
+   Copyright (C) 2015 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/>.  */
+
+int
+f2 (void)
+{
+  return 43;
+}
diff --git a/elf/tst-auditmod11.c b/elf/tst-auditmod11.c
new file mode 100644
index 0000000..cfcb34f
--- /dev/null
+++ b/elf/tst-auditmod11.c
@@ -0,0 +1,39 @@
+/* Audit module for tst-audit11.
+   Copyright (C) 2015 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 <link.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+unsigned int
+la_version (unsigned int version)
+{
+  return version;
+}
+
+char *
+la_objsearch (const char *name, uintptr_t *cookie, unsigned int flag)
+{
+  if (strcmp (name, "tst-audit11mod2.so") == 0)
+    {
+      return (char *) "$ORIGIN/tst-audit11mod2.so";
+    }
+  return (char *) name;
+}
diff --git a/elf/tst-auditmod12.c b/elf/tst-auditmod12.c
new file mode 100644
index 0000000..0c532bd
--- /dev/null
+++ b/elf/tst-auditmod12.c
@@ -0,0 +1,43 @@
+/* Audit module for tst-audit12.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <link.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+unsigned int
+la_version (unsigned int version)
+{
+  return version;
+}
+
+char *
+la_objsearch (const char *name, uintptr_t *cookie, unsigned int flag)
+{
+  const char target[] = "tst-audit12mod2.so";
+
+  size_t namelen = strlen (name);
+  if (namelen >= sizeof (target) - 1
+      && strcmp (name + namelen - (sizeof (target) - 1), target) == 0)
+    {
+      return (char *) "$ORIGIN/tst-audit12mod3.so";
+    }
+  return (char *) name;
+}
diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
index 317605b..e446f15 100644
--- a/sysdeps/mach/hurd/dl-sysdep.c
+++ b/sysdeps/mach/hurd/dl-sysdep.c
@@ -186,7 +186,7 @@ unfmh();			/* XXX */
 	    assert_perror (err);
 
 	    lastslash = strrchr (p, '/');
-	    l = _dl_map_object_from_fd (lastslash ? lastslash + 1 : p,
+	    l = _dl_map_object_from_fd (lastslash ? lastslash + 1 : p, NULL,
 					memobj, strdup (p), 0);
 
 	    /* Squirrel away the memory object port where it
-- 
2.4.3


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