An application that erroneously tries to repeatedly dlopen("a.out", ...)
may hit assertion failure:

  Inconsistency detected by ld.so: dl-tls.c: 474: _dl_allocate_tls_init:
  Assertion `listp != ((void *)0)' failed!

dlopen() actually fails with  "./a.out: cannot dynamically load executable",
but it does so after incrementing dl_tls_max_dtv_idx.

Once we run out of TLS_SLOTINFO_SURPLUS (62), we exit with above assertion
failure.

2014-03-24  Paul Pluzhnikov  <ppluzhnikov@google.com>

	[BZ #16634]

	* elf/dl-load.c (open_verify): Add mode parameter.
        Error early when ET_EXEC and mode does not have __RTLD_OPENEXEC.
        (open_path): Change from boolean 'secure' to complete flag 'mode'
        (_dl_map_object): Adjust.
	* elf/Makefile (tests): Add tst-dlopen-aout.
	* elf/tst-dlopen-aout.c: New test.
This commit is contained in:
Paul Pluzhnikov 2014-03-24 10:58:26 -07:00
parent 509361270b
commit a42faf59d6
5 changed files with 101 additions and 16 deletions

View File

@ -1,3 +1,14 @@
2014-03-24 Paul Pluzhnikov <ppluzhnikov@google.com>
[BZ #16634]
* elf/dl-load.c (open_verify): Add mode parameter.
Error early when ET_EXEC and mode does not have __RTLD_OPENEXEC.
(open_path): Change from boolean 'secure' to complete flag 'mode'
(_dl_map_object): Adjust.
* elf/Makefile (tests): Add tst-dlopen-aout.
* elf/tst-dlopen-aout.c: New test.
2014-03-24 Stefan Liebler <stli@linux.vnet.ibm.com>
[BZ #16714]

6
NEWS
View File

@ -10,9 +10,9 @@ Version 2.20
* The following bugs are resolved with this release:
15347, 15804, 15894, 16002, 16284, 16447, 16532, 16545, 16574, 16600,
16609, 16610, 16611, 16613, 16623, 16632, 16639, 16642, 16649, 16670,
16674, 16677, 16680, 16683, 16689, 16695, 16701, 16706, 16707, 16731,
16743.
16609, 16610, 16611, 16613, 16623, 16632, 16634, 16639, 16642, 16649,
16670, 16674, 16677, 16680, 16683, 16689, 16695, 16701, 16706, 16707,
16731, 16743.
* Running the testsuite no longer terminates as soon as a test fails.
Instead, a file tests.sum (xtests.sum from "make xcheck") is generated,

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@ -148,7 +148,7 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
tst-stackguard1 tst-addr1 tst-thrlock \
tst-unique1 tst-unique2 tst-unique3 tst-unique4 \
tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \
tst-ptrguard1
tst-ptrguard1 tst-dlopen-aout
# reldep9
test-srcs = tst-pathopt
selinux-enabled := $(shell cat /selinux/enforce 2> /dev/null)
@ -1056,6 +1056,7 @@ tst-leaks1-static-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1-static.mtrace
$(objpfx)tst-addr1: $(libdl)
$(objpfx)tst-thrlock: $(libdl) $(shared-thread-library)
$(objpfx)tst-dlopen-aout: $(libdl) $(shared-thread-library)
CFLAGS-ifuncmain1pic.c += $(pic-ccflag)
CFLAGS-ifuncmain1picstatic.c += $(pic-ccflag)

View File

@ -1667,7 +1667,7 @@ print_search_path (struct r_search_path_elem **list,
user might want to know about this. */
static int
open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
int whatcode, bool *found_other_class, bool free_name)
int whatcode, int mode, bool *found_other_class, bool free_name)
{
/* This is the expected ELF header. */
#define ELF32_CLASS ELFCLASS32
@ -1843,6 +1843,17 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
errstring = N_("only ET_DYN and ET_EXEC can be loaded");
goto call_lose;
}
else if (__glibc_unlikely (ehdr->e_type == ET_EXEC
&& (mode & __RTLD_OPENEXEC) == 0))
{
/* BZ #16634. It is an error to dlopen ET_EXEC (unless
__RTLD_OPENEXEC is explicitly set). We return error here
so that code in _dl_map_object_from_fd does not try to set
l_tls_modid for this module. */
errstring = N_("cannot dynamically load executable");
goto call_lose;
}
else if (__builtin_expect (ehdr->e_phentsize, sizeof (ElfW(Phdr)))
!= sizeof (ElfW(Phdr)))
{
@ -1928,7 +1939,7 @@ open_verify (const char *name, struct filebuf *fbp, struct link_map *loader,
if MAY_FREE_DIRS is true. */
static int
open_path (const char *name, size_t namelen, int secure,
open_path (const char *name, size_t namelen, int mode,
struct r_search_path_struct *sps, char **realname,
struct filebuf *fbp, struct link_map *loader, int whatcode,
bool *found_other_class)
@ -1980,8 +1991,8 @@ open_path (const char *name, size_t namelen, int secure,
if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS))
_dl_debug_printf (" trying file=%s\n", buf);
fd = open_verify (buf, fbp, loader, whatcode, found_other_class,
false);
fd = open_verify (buf, fbp, loader, whatcode, mode,
found_other_class, false);
if (this_dir->status[cnt] == unknown)
{
if (fd != -1)
@ -2010,7 +2021,7 @@ open_path (const char *name, size_t namelen, int secure,
/* Remember whether we found any existing directory. */
here_any |= this_dir->status[cnt] != nonexisting;
if (fd != -1 && __builtin_expect (secure, 0)
if (fd != -1 && __builtin_expect (mode & __RTLD_SECURE, 0)
&& INTUSE(__libc_enable_secure))
{
/* This is an extra security effort to make sure nobody can
@ -2184,7 +2195,7 @@ _dl_map_object (struct link_map *loader, const char *name,
for (l = loader; l; l = l->l_loader)
if (cache_rpath (l, &l->l_rpath_dirs, DT_RPATH, "RPATH"))
{
fd = open_path (name, namelen, mode & __RTLD_SECURE,
fd = open_path (name, namelen, mode,
&l->l_rpath_dirs,
&realname, &fb, loader, LA_SER_RUNPATH,
&found_other_class);
@ -2200,7 +2211,7 @@ _dl_map_object (struct link_map *loader, const char *name,
&& main_map != NULL && main_map->l_type != lt_loaded
&& cache_rpath (main_map, &main_map->l_rpath_dirs, DT_RPATH,
"RPATH"))
fd = open_path (name, namelen, mode & __RTLD_SECURE,
fd = open_path (name, namelen, mode,
&main_map->l_rpath_dirs,
&realname, &fb, loader ?: main_map, LA_SER_RUNPATH,
&found_other_class);
@ -2208,7 +2219,7 @@ _dl_map_object (struct link_map *loader, const char *name,
/* Try the LD_LIBRARY_PATH environment variable. */
if (fd == -1 && env_path_list.dirs != (void *) -1)
fd = open_path (name, namelen, mode & __RTLD_SECURE, &env_path_list,
fd = open_path (name, namelen, mode, &env_path_list,
&realname, &fb,
loader ?: GL(dl_ns)[LM_ID_BASE]._ns_loaded,
LA_SER_LIBPATH, &found_other_class);
@ -2217,7 +2228,7 @@ _dl_map_object (struct link_map *loader, const char *name,
if (fd == -1 && loader != NULL
&& cache_rpath (loader, &loader->l_runpath_dirs,
DT_RUNPATH, "RUNPATH"))
fd = open_path (name, namelen, mode & __RTLD_SECURE,
fd = open_path (name, namelen, mode,
&loader->l_runpath_dirs, &realname, &fb, loader,
LA_SER_RUNPATH, &found_other_class);
@ -2267,7 +2278,8 @@ _dl_map_object (struct link_map *loader, const char *name,
{
fd = open_verify (cached,
&fb, loader ?: GL(dl_ns)[nsid]._ns_loaded,
LA_SER_CONFIG, &found_other_class, false);
LA_SER_CONFIG, mode, &found_other_class,
false);
if (__glibc_likely (fd != -1))
{
realname = local_strdup (cached);
@ -2287,7 +2299,7 @@ _dl_map_object (struct link_map *loader, const char *name,
&& ((l = loader ?: GL(dl_ns)[nsid]._ns_loaded) == NULL
|| __builtin_expect (!(l->l_flags_1 & DF_1_NODEFLIB), 1))
&& rtld_search_dirs.dirs != (void *) -1)
fd = open_path (name, namelen, mode & __RTLD_SECURE, &rtld_search_dirs,
fd = open_path (name, namelen, mode, &rtld_search_dirs,
&realname, &fb, l, LA_SER_DEFAULT, &found_other_class);
/* Add another newline when we are tracing the library loading. */
@ -2305,7 +2317,7 @@ _dl_map_object (struct link_map *loader, const char *name,
else
{
fd = open_verify (realname, &fb,
loader ?: GL(dl_ns)[nsid]._ns_loaded, 0,
loader ?: GL(dl_ns)[nsid]._ns_loaded, 0, mode,
&found_other_class, true);
if (__builtin_expect (fd, 0) == -1)
free (realname);

61
elf/tst-dlopen-aout.c Normal file
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@ -0,0 +1,61 @@
/* Test case for BZ #16634.
Copyright (C) 2014 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/>.
Note: this test currently only fails when glibc is configured with
--enable-hardcoded-path-in-tests. */
#include <assert.h>
#include <dlfcn.h>
#include <stdio.h>
#include <pthread.h>
__thread int x;
void *
fn (void *p)
{
return p;
}
int
main (int argc, char *argv[])
{
int j;
for (j = 0; j < 100; ++j)
{
pthread_t thr;
void *p;
int rc;
p = dlopen (argv[0], RTLD_LAZY);
if (p != NULL)
{
fprintf (stderr, "dlopen unexpectedly succeeded\n");
return 1;
}
rc = pthread_create (&thr, NULL, fn, NULL);
assert (rc == 0);
rc = pthread_join (thr, NULL);
assert (rc == 0);
}
return 0;
}