elf: Do not fail for failed dlopem on audit modules (BZ #28061)

The dl_main() sets the LM_ID_BASE to RT_ADD just before starting to
add load new shared objects.  The state is set to R_CONSISTENT just
after all objects are loaded.

However if a audit modules tries to dlmopen() an inexistent module,
the _dl_open() will assert that the namespace is in an inconsistent
state.

This is different than dlopen(), since first it will not use
LM_ID_BASE and second _dl_map_object_from_fd() is the sole responsible
to set and reset the r_state value.

So the assert() on _dl_open() can not really see if the state is
consistent since it is _dt_main() that reset is.  This patch removes
the assert.

Checked on x86_64-linux-gnu.

4 files changed, 87 insertions, 2 deletions

diff --git a/elf/Makefile b/elf/Makefile
index 174198e132..2ffbe641ae 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -221,6 +221,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
 	 tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen \
 	 tst-audit14 tst-audit15 tst-audit16 tst-audit17 \
 	 tst-audit18a tst-audit18b \
+	 tst-audit19 \
 	 tst-single_threaded tst-single_threaded-pthread \
 	 tst-tls-ie tst-tls-ie-dlmopen argv0test \
 	 tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
@@ -306,6 +307,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
 		tst-unique2mod1 tst-unique2mod2 \
 		tst-auditmod9a tst-auditmod9b \
 		tst-auditmod18a tst-auditmod18b tst-audit18bmod \
+		tst-auditmod19 \
 		$(if $(CXX),tst-unique3lib tst-unique3lib2 tst-unique4lib \
 		  tst-nodelete-uniquemod tst-nodelete-rtldmod \
 		  tst-nodelete-zmod \
@@ -1512,6 +1514,9 @@ $(objpfx)tst-audit18b.out: $(objpfx)tst-auditmod18b.so
 $(objpfx)tst-audit18b: $(objpfx)tst-audit18bmod.so
 tst-audit18b-ARGS = -- $(host-test-program-cmd)
 
+$(objpfx)tst-audit19.out: $(objpfx)tst-auditmod19.so
+tst-audit19-ENV = LD_AUDIT=$(objpfx)tst-auditmod19.so
+
 # tst-sonamemove links against an older implementation of the library.
 LDFLAGS-tst-sonamemove-linkmod1.so = \
   -Wl,--version-script=tst-sonamemove-linkmod1.map \
diff --git a/elf/dl-open.c b/elf/dl-open.c
index ec386626f9..f25340968f 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -899,8 +899,6 @@ no more namespaces available for dlmopen()"));
 	     the flag here.  */
 	}
 
-      assert (_dl_debug_initialize (0, args.nsid)->r_state == RT_CONSISTENT);
-
       /* Release the lock.  */
       __rtld_lock_unlock_recursive (GL(dl_load_lock));
 
diff --git a/elf/tst-audit19.c b/elf/tst-audit19.c
new file mode 100644
index 0000000000..6f39ccee86
--- /dev/null
+++ b/elf/tst-audit19.c
@@ -0,0 +1,25 @@
+/* Check dlopen failure on audit modules.
+   Copyright (C) 2021 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
+   <https://www.gnu.org/licenses/>.  */
+
+static int
+do_test (void)
+{
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/elf/tst-auditmod19.c b/elf/tst-auditmod19.c
new file mode 100644
index 0000000000..c57e50ee4e
--- /dev/null
+++ b/elf/tst-auditmod19.c
@@ -0,0 +1,57 @@
+/* Check dlopen failure on audit modules.
+   Copyright (C) 2021 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+#include <link.h>
+#include <stdlib.h>
+
+unsigned int
+la_version (unsigned int v)
+{
+  return LAV_CURRENT;
+}
+
+static void
+check (void)
+{
+  {
+    void *mod = dlopen ("nonexistent.so", RTLD_NOW);
+    if (mod != NULL)
+      abort ();
+  }
+
+  {
+    void *mod = dlmopen (LM_ID_BASE, "nonexistent.so", RTLD_NOW);
+    if (mod != NULL)
+      abort ();
+  }
+}
+
+void
+la_activity (uintptr_t *cookie, unsigned int flag)
+{
+  if (flag != LA_ACT_CONSISTENT)
+    return;
+  check ();
+}
+
+void
+la_preinit (uintptr_t *cookie)
+{
+  check ();
+}