From 8e889c5da3c5981c5a46a93fec02de40131ac5a6 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 23 Jan 2019 11:42:54 -0200 Subject: [PATCH] elf: Fix LD_AUDIT for modules with invalid version (BZ#24122) The error handling patch for invalid audit modules version access invalid memory: elf/rtld.c: 1454 unsigned int (*laversion) (unsigned int); 1455 unsigned int lav; 1456 if (err_str == NULL 1457 && (laversion = largs.result) != NULL 1458 && (lav = laversion (LAV_CURRENT)) > 0 1459 && lav <= LAV_CURRENT) 1460 { [...] 1526 else 1527 { 1528 /* We cannot use the DSO, it does not have the 1529 appropriate interfaces or it expects something 1530 more recent. */ 1531 #ifndef NDEBUG 1532 Lmid_t ns = dlmargs.map->l_ns; 1533 #endif 1534 _dl_close (dlmargs.map); 1535 1536 /* Make sure the namespace has been cleared entirely. */ 1537 assert (GL(dl_ns)[ns]._ns_loaded == NULL); 1538 assert (GL(dl_ns)[ns]._ns_nloaded == 0); 1539 1540 GL(dl_tls_max_dtv_idx) = tls_idx; 1541 goto not_loaded; 1542 } 1431 const char *err_str = NULL; 1432 bool malloced; 1433 (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit, 1434 &dlmargs); 1435 if (__glibc_unlikely (err_str != NULL)) 1436 { 1437 not_loaded: 1438 _dl_error_printf ("\ 1439 ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", 1440 name, err_str); 1441 if (malloced) 1442 free ((char *) err_str); 1443 } On failure the err_str will be NULL and _dl_debug_vdprintf does not handle it properly: elf/dl-misc.c: 200 case 's': 201 /* Get the string argument. */ 202 iov[niov].iov_base = va_arg (arg, char *); 203 iov[niov].iov_len = strlen (iov[niov].iov_base); 204 if (prec != -1) 205 iov[niov].iov_len = MIN ((size_t) prec, iov[niov].iov_len); 206 ++niov; 207 break; This patch fixes the issues and improves the error message. Checked on x86_64-linux-gnu and i686-linux-gnu [BZ #24122] * elf/Makefile (tests): Add tst-audit13. (modules-names): Add tst-audit13mod1. (tst-audit13.out, LDFLAGS-tst-audit13mod1.so, tst-audit13-ENV): New rule. * elf/rtld.c (dl_main): Handle invalid audit module version. * elf/tst-audit13.c: New file. * elf/tst-audit13mod1.c: Likewise. Reviewed-by: Carlos O'Donell --- ChangeLog | 11 +++++ elf/Makefile | 9 ++++- elf/rtld.c | 30 +++++++++++--- elf/tst-audit13.c | 28 +++++++++++++ elf/tst-audit13mod1.c | 93 +++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 164 insertions(+), 7 deletions(-) create mode 100644 elf/tst-audit13.c create mode 100644 elf/tst-audit13mod1.c diff --git a/ChangeLog b/ChangeLog index fed239cf3c..dfad23b0c5 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,14 @@ +2019-01-24 Adhemerval Zanella + + [BZ #24122] + * elf/Makefile (tests): Add tst-audit13. + (modules-names): Add tst-audit13mod1. + (tst-audit13.out, LDFLAGS-tst-audit13mod1.so, tst-audit13-ENV): New + rule. + * elf/rtld.c (dl_main): Handle invalid audit module version. + * elf/tst-audit13.c: New file. + * elf/tst-audit13mod1.c: Likewise. + 2019-01-22 Samuel Thibault * sysdeps/mach/hurd/faccessat.c (__faccessat_common): Check for errors diff --git a/elf/Makefile b/elf/Makefile index 9cf5cd8dfd..c24d765730 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -187,7 +187,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-nodelete2 tst-audit11 tst-audit12 tst-dlsym-error tst-noload \ tst-latepthread tst-tls-manydynamic tst-nodelete-dlclose \ tst-debug1 tst-main1 tst-absolute-sym tst-absolute-zero tst-big-note \ - tst-unwind-ctor tst-unwind-main + tst-unwind-ctor tst-unwind-main tst-audit13 # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -275,7 +275,8 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-latepthreadmod $(tst-tls-many-dynamic-modules) \ tst-nodelete-dlclose-dso tst-nodelete-dlclose-plugin \ tst-main1mod tst-libc_dlvsym-dso tst-absolute-sym-lib \ - tst-absolute-zero-lib tst-big-note-lib tst-unwind-ctor-lib + tst-absolute-zero-lib tst-big-note-lib tst-unwind-ctor-lib \ + tst-audit13mod1 # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\ @@ -1382,6 +1383,10 @@ tst-audit12-ENV = LD_AUDIT=$(objpfx)tst-auditmod12.so $(objpfx)tst-audit12mod1.so: $(objpfx)tst-audit12mod2.so LDFLAGS-tst-audit12mod2.so = -Wl,--version-script=tst-audit12mod2.map +$(objpfx)tst-audit13.out: $(objpfx)tst-audit13mod1.so +LDFLAGS-tst-audit13mod1.so = -Wl,-z,lazy +tst-audit13-ENV = LD_AUDIT=$(objpfx)tst-audit13mod1.so + # Override -z defs, so that we can reference an undefined symbol. # Force lazy binding for the same reason. LDFLAGS-tst-latepthreadmod.so = \ diff --git a/elf/rtld.c b/elf/rtld.c index 5d97f41b7b..9e0f752482 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1453,10 +1453,12 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", unsigned int (*laversion) (unsigned int); unsigned int lav; - if (err_str == NULL - && (laversion = largs.result) != NULL - && (lav = laversion (LAV_CURRENT)) > 0 - && lav <= LAV_CURRENT) + if (err_str != NULL) + goto not_loaded; + + if ((laversion = largs.result) != NULL + && (lav = laversion (LAV_CURRENT)) > 0 + && lav <= LAV_CURRENT) { /* Allocate structure for the callback function pointers. This call can never fail. */ @@ -1538,7 +1540,25 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", assert (GL(dl_ns)[ns]._ns_nloaded == 0); GL(dl_tls_max_dtv_idx) = tls_idx; - goto not_loaded; + if (GLRO(dl_debug_mask) & DL_DEBUG_FILES) + { + _dl_debug_printf ("\ +\nfile=%s cannot be loaded as audit interface; ignored.\n", name); + if (laversion == NULL) + _dl_debug_printf ( +" la_version function not found.\n"); + else + { + if (lav == 0) + _dl_debug_printf ( +" auditor requested to be ignored (returned version of 0).\n"); + else + _dl_debug_printf ( +" auditor disabled since expected version %d is greater than " +"supported version %d.\n", + lav, LAV_CURRENT); + } + } } } } diff --git a/elf/tst-audit13.c b/elf/tst-audit13.c new file mode 100644 index 0000000000..6f587baf58 --- /dev/null +++ b/elf/tst-audit13.c @@ -0,0 +1,28 @@ +/* Check for invalid audit version (BZ#24122). + Copyright (C) 2019 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 + . */ + +#include + +static int +do_test (void) +{ + puts ("plt call"); + return 0; +} + +#include diff --git a/elf/tst-audit13mod1.c b/elf/tst-audit13mod1.c new file mode 100644 index 0000000000..cf017e235c --- /dev/null +++ b/elf/tst-audit13mod1.c @@ -0,0 +1,93 @@ +/* Check for invalid audit version (BZ#24122). + Copyright (C) 2019 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 + . */ + +#include +#include + +unsigned int +la_version (unsigned int version) +{ + /* The audit specification says that a version of 0 or a version + greater than any version supported by the dynamic loader shall + cause the module to be ignored. */ + return 0; +} + +void +la_activity (uintptr_t *cookie, unsigned int flag) +{ + exit (EXIT_FAILURE); +} + +char * +la_objsearch (const char *name, uintptr_t *cookie, unsigned int flag) +{ + exit (EXIT_FAILURE); +} + +unsigned int +la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t * cookie) +{ + exit (EXIT_FAILURE); +} + +void +la_preinit (uintptr_t * cookie) +{ + exit (EXIT_FAILURE); +} + +uintptr_t +#if __ELF_NATIVE_CLASS == 32 +la_symbind32 (Elf32_Sym *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, unsigned int *flags, const char *symname) +#else +la_symbind64 (Elf64_Sym *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, unsigned int *flags, const char *symname) +#endif +{ + exit (EXIT_FAILURE); +} + +unsigned int +la_objclose (uintptr_t * cookie) +{ + exit (EXIT_FAILURE); +} + +#include +#if (!defined (pltenter) || !defined (pltexit) || !defined (La_regs) \ + || !defined (La_retval) || !defined (int_retval)) +# error "architecture specific code needed in sysdeps/CPU/tst-audit.h" +#endif + +ElfW(Addr) +pltenter (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, La_regs *regs, unsigned int *flags, + const char *symname, long int *framesizep) +{ + exit (EXIT_FAILURE); +} + +unsigned int +pltexit (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook, + uintptr_t *defcook, const La_regs *inregs, La_retval *outregs, + const char *symname) +{ + exit (EXIT_FAILURE); +} -- 2.43.5