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* [glibc/release/2.33/master] elf: Call __libc_early_init for reused namespaces (bug 29528)
@ 2022-08-30 15:09 Florian Weimer
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From: Florian Weimer @ 2022-08-30 15:09 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=da7afc97ad9ddc817686d61f046277166ef42644
commit da7afc97ad9ddc817686d61f046277166ef42644
Author: Florian Weimer <fweimer@redhat.com>
Date: Fri Aug 26 21:15:43 2022 +0200
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)
Diff:
---
NEWS | 1 +
elf/Makefile | 8 ++++++-
elf/dl-open.c | 13 +++++++-----
elf/tst-dlmopen-twice-mod1.c | 37 ++++++++++++++++++++++++++++++++
elf/tst-dlmopen-twice-mod2.c | 50 ++++++++++++++++++++++++++++++++++++++++++++
elf/tst-dlmopen-twice.c | 34 ++++++++++++++++++++++++++++++
6 files changed, 137 insertions(+), 6 deletions(-)
diff --git a/NEWS b/NEWS
index bd86d8971c..3caeab36d9 100644
--- a/NEWS
+++ b/NEWS
@@ -64,6 +64,7 @@ The following bugs are resolved with this release:
[28770] CVE-2021-3998: Unexpected return value from realpath() for too long results
[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
\f
Version 2.33
diff --git a/elf/Makefile b/elf/Makefile
index 37944c189c..f408a19e8f 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -227,7 +227,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
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 \
- tst-dlmopen-dlerror tst-dlmopen-gethostbyname
+ tst-dlmopen-dlerror tst-dlmopen-gethostbyname tst-dlmopen-twice
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@@ -352,6 +352,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
libmarkermod5-1 libmarkermod5-2 libmarkermod5-3 libmarkermod5-4 \
libmarkermod5-5 \
tst-dlmopen-dlerror-mod tst-dlmopen-gethostbyname-mod \
+ tst-dlmopen-twice-mod1 tst-dlmopen-twice-mod2 \
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
@@ -1934,3 +1935,8 @@ $(objpfx)tst-rtld-help.out: $(objpfx)ld.so
$(objpfx)tst-dlmopen-gethostbyname: $(libdl)
$(objpfx)tst-dlmopen-gethostbyname.out: $(objpfx)tst-dlmopen-gethostbyname-mod.so
+
+$(objpfx)tst-dlmopen-twice: $(libdl)
+$(objpfx)tst-dlmopen-twice.out: \
+ $(objpfx)tst-dlmopen-twice-mod1.so \
+ $(objpfx)tst-dlmopen-twice-mod2.so
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 1b965457c4..08cf5a02ad 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -819,11 +819,14 @@ _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;
}
diff --git a/elf/tst-dlmopen-twice-mod1.c b/elf/tst-dlmopen-twice-mod1.c
new file mode 100644
index 0000000000..0eaf04948c
--- /dev/null
+++ b/elf/tst-dlmopen-twice-mod1.c
@@ -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];
diff --git a/elf/tst-dlmopen-twice-mod2.c b/elf/tst-dlmopen-twice-mod2.c
new file mode 100644
index 0000000000..40c6c01f96
--- /dev/null
+++ b/elf/tst-dlmopen-twice-mod2.c
@@ -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;
+}
diff --git a/elf/tst-dlmopen-twice.c b/elf/tst-dlmopen-twice.c
new file mode 100644
index 0000000000..449f3c8fa9
--- /dev/null
+++ b/elf/tst-dlmopen-twice.c
@@ -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>
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