2
0
mirror of git://sourceware.org/git/glibc.git synced 2025-04-24 14:41:06 +08:00

elf: Call __libc_early_init for reused namespaces (bug 29528)

libc_map is never reset to NULL, neither during dlclose nor on a
dlopen call which reuses the namespace structure.  As a result, if a
namespace is reused, its libc is not initialized properly.  The most
visible result is a crash in the <ctype.h> functions.

To prevent similar bugs on namespace reuse from surfacing,
unconditionally initialize the chosen namespace to zero using memset.

(cherry picked from commit d0e357ff45a75553dee3b17ed7d303bfa544f6fe)
This commit is contained in:
Florian Weimer 2022-08-26 21:15:43 +02:00
parent 6f8c9dc8bb
commit 51b72ac04b
6 changed files with 138 additions and 7 deletions

1
NEWS

@ -30,6 +30,7 @@ The following bugs are resolved with this release:
[28755] overflow bug in wcsncmp_avx2 and wcsncmp_evex
[28896] strncmp-avx2-rtm and wcsncmp-avx2-rtm fallback on non-rtm
variants when avoiding overflow
[29528] elf: Call __libc_early_init for reused namespaces
Version 2.32

@ -210,7 +210,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen \
tst-audit14 tst-audit15 tst-audit16 \
tst-single_threaded tst-single_threaded-pthread \
tst-tls-ie tst-tls-ie-dlmopen
tst-tls-ie tst-tls-ie-dlmopen tst-dlmopen-twice
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@ -328,7 +328,8 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-single_threaded-mod3 tst-single_threaded-mod4 \
tst-tls-ie-mod0 tst-tls-ie-mod1 tst-tls-ie-mod2 \
tst-tls-ie-mod3 tst-tls-ie-mod4 tst-tls-ie-mod5 \
tst-tls-ie-mod6
tst-tls-ie-mod6 \
tst-dlmopen-twice-mod1 tst-dlmopen-twice-mod2 \
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
@ -1796,3 +1797,8 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
$(objpfx)tst-tls-ie-mod6.so
$(objpfx)tst-tls-surplus: $(libdl)
$(objpfx)tst-dlmopen-twice: $(libdl)
$(objpfx)tst-dlmopen-twice.out: \
$(objpfx)tst-dlmopen-twice-mod1.so \
$(objpfx)tst-dlmopen-twice-mod2.so

@ -825,11 +825,14 @@ _dl_open (const char *file, int mode, const void *caller_dlopen, Lmid_t nsid,
_dl_signal_error (EINVAL, file, NULL, N_("\
no more namespaces available for dlmopen()"));
}
else if (nsid == GL(dl_nns))
{
__rtld_lock_initialize (GL(dl_ns)[nsid]._ns_unique_sym_table.lock);
++GL(dl_nns);
}
if (nsid == GL(dl_nns))
++GL(dl_nns);
/* Initialize the new namespace. Most members are
zero-initialized, only the lock needs special treatment. */
memset (&GL(dl_ns)[nsid], 0, sizeof (GL(dl_ns)[nsid]));
__rtld_lock_initialize (GL(dl_ns)[nsid]._ns_unique_sym_table.lock);
_dl_debug_initialize (0, nsid)->r_state = RT_CONSISTENT;
}

@ -0,0 +1,37 @@
/* Initialization of libc after dlmopen/dlclose/dlmopen (bug 29528). Module 1.
Copyright (C) 2022 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 <stdio.h>
static void __attribute__ ((constructor))
init (void)
{
puts ("info: tst-dlmopen-twice-mod1.so loaded");
fflush (stdout);
}
static void __attribute__ ((destructor))
fini (void)
{
puts ("info: tst-dlmopen-twice-mod1.so about to be unloaded");
fflush (stdout);
}
/* Large allocation. The second module does not have this, so it
should load libc at a different address. */
char large_allocate[16 * 1024 * 1024];

@ -0,0 +1,50 @@
/* Initialization of libc after dlmopen/dlclose/dlmopen (bug 29528). Module 2.
Copyright (C) 2022 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 <ctype.h>
#include <stdio.h>
static void __attribute__ ((constructor))
init (void)
{
puts ("info: tst-dlmopen-twice-mod2.so loaded");
fflush (stdout);
}
static void __attribute__ ((destructor))
fini (void)
{
puts ("info: tst-dlmopen-twice-mod2.so about to be unloaded");
fflush (stdout);
}
int
run_check (void)
{
puts ("info: about to call isalpha");
fflush (stdout);
volatile char ch = 'a';
if (!isalpha (ch))
{
puts ("error: isalpha ('a') is not true");
fflush (stdout);
return 1;
}
return 0;
}

34
elf/tst-dlmopen-twice.c Normal file

@ -0,0 +1,34 @@
/* Initialization of libc after dlmopen/dlclose/dlmopen (bug 29528). Main.
Copyright (C) 2022 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 <support/xdlfcn.h>
#include <support/check.h>
static int
do_test (void)
{
void *handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-twice-mod1.so", RTLD_NOW);
xdlclose (handle);
handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-twice-mod2.so", RTLD_NOW);
int (*run_check) (void) = xdlsym (handle, "run_check");
TEST_COMPARE (run_check (), 0);
xdlclose (handle);
return 0;
}
#include <support/test-driver.c>