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authorPaul Pluzhnikov <ppluzhnikov@google.com>2014-03-24 10:58:26 -0700
committerPaul Pluzhnikov <ppluzhnikov@google.com>2014-03-24 10:58:26 -0700
commita42faf59d6d9f82e5293a9ebcc26d9c9e562b12b (patch)
treea124669e62343e6b318af03c82a86a807773c334 /elf
parent509361270b4b889e991400a70eb87d45304c01cd (diff)
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Fix BZ #16634.
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.
Diffstat (limited to 'elf')
-rw-r--r--elf/Makefile3
-rw-r--r--elf/dl-load.c36
-rw-r--r--elf/tst-dlopen-aout.c61
3 files changed, 87 insertions, 13 deletions
diff --git a/elf/Makefile b/elf/Makefile
index df138fc..d96cd40 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -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)
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 8ebc128..9455df2 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -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);
diff --git a/elf/tst-dlopen-aout.c b/elf/tst-dlopen-aout.c
new file mode 100644
index 0000000..d353425
--- /dev/null
+++ b/elf/tst-dlopen-aout.c
@@ -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;
+}