Message ID | 87fshiq3kc.fsf@oldenburg.str.redhat.com |
---|---|
State | New |
Headers | show |
Series | [v2] elf: Call __libc_early_init for reused namespaces (bug 29528) | expand |
On Fri, Aug 26, 2022 at 11:10 AM Florian Weimer <fweimer@redhat.com> wrote: > > 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. > > --- > v2: Fix C&P error in trace message. > elf/Makefile | 7 +++++++ > 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 ++++++++++++++++++++++++++++++ > 5 files changed, 136 insertions(+), 5 deletions(-) > > diff --git a/elf/Makefile b/elf/Makefile > index 3928a08787..008770bfaf 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -410,6 +410,7 @@ tests += \ > tst-dlmopen4 \ > tst-dlmopen-dlerror \ > tst-dlmopen-gethostbyname \ > + tst-dlmopen-twice \ > tst-dlopenfail \ > tst-dlopenfail-2 \ > tst-dlopenrpath \ > @@ -839,6 +840,8 @@ modules-names += \ > tst-dlmopen1mod \ > tst-dlmopen-dlerror-mod \ > tst-dlmopen-gethostbyname-mod \ > + tst-dlmopen-twice-mod1 \ > + tst-dlmopen-twice-mod2 \ > tst-dlopenfaillinkmod \ > tst-dlopenfailmod1 \ > tst-dlopenfailmod2 \ > @@ -2976,3 +2979,7 @@ $(objpfx)tst-audit-tlsdesc.out: $(objpfx)tst-auditmod-tlsdesc.so > tst-audit-tlsdesc-ENV = LD_AUDIT=$(objpfx)tst-auditmod-tlsdesc.so > $(objpfx)tst-audit-tlsdesc-dlopen.out: $(objpfx)tst-auditmod-tlsdesc.so > tst-audit-tlsdesc-dlopen-ENV = LD_AUDIT=$(objpfx)tst-auditmod-tlsdesc.so > + > +$(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 a23e65926b..46e8066fd8 100644 > --- a/elf/dl-open.c > +++ b/elf/dl-open.c > @@ -844,11 +844,14 @@ _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_update (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> > > base-commit: 5ecc98241229d494aaad23a4a3fe106fe11e1f40 > LGTM. Thanks.
diff --git a/elf/Makefile b/elf/Makefile index 3928a08787..008770bfaf 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -410,6 +410,7 @@ tests += \ tst-dlmopen4 \ tst-dlmopen-dlerror \ tst-dlmopen-gethostbyname \ + tst-dlmopen-twice \ tst-dlopenfail \ tst-dlopenfail-2 \ tst-dlopenrpath \ @@ -839,6 +840,8 @@ modules-names += \ tst-dlmopen1mod \ tst-dlmopen-dlerror-mod \ tst-dlmopen-gethostbyname-mod \ + tst-dlmopen-twice-mod1 \ + tst-dlmopen-twice-mod2 \ tst-dlopenfaillinkmod \ tst-dlopenfailmod1 \ tst-dlopenfailmod2 \ @@ -2976,3 +2979,7 @@ $(objpfx)tst-audit-tlsdesc.out: $(objpfx)tst-auditmod-tlsdesc.so tst-audit-tlsdesc-ENV = LD_AUDIT=$(objpfx)tst-auditmod-tlsdesc.so $(objpfx)tst-audit-tlsdesc-dlopen.out: $(objpfx)tst-auditmod-tlsdesc.so tst-audit-tlsdesc-dlopen-ENV = LD_AUDIT=$(objpfx)tst-auditmod-tlsdesc.so + +$(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 a23e65926b..46e8066fd8 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -844,11 +844,14 @@ _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_update (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>