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author | Florian Weimer <fweimer@redhat.com> | 2022-08-26 21:15:43 +0200 |
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committer | Florian Weimer <fweimer@redhat.com> | 2022-08-30 16:53:14 +0200 |
commit | da7afc97ad9ddc817686d61f046277166ef42644 (patch) | |
tree | 651343f949fc59f6782fc1c389fb1f10e1d0cd06 | |
parent | 0631ff369dd3986f7e66dfac03f1233d8cd74045 (diff) | |
download | glibc-da7afc97ad9ddc817686d61f046277166ef42644.tar.gz glibc-da7afc97ad9ddc817686d61f046277166ef42644.tar.xz glibc-da7afc97ad9ddc817686d61f046277166ef42644.zip |
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)
-rw-r--r-- | NEWS | 1 | ||||
-rw-r--r-- | elf/Makefile | 8 | ||||
-rw-r--r-- | elf/dl-open.c | 13 | ||||
-rw-r--r-- | elf/tst-dlmopen-twice-mod1.c | 37 | ||||
-rw-r--r-- | elf/tst-dlmopen-twice-mod2.c | 50 | ||||
-rw-r--r-- | 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 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> |