Message ID | 20240112182337.595413-1-josimmon@redhat.com |
---|---|
State | New |
Headers | show |
Series | [v5] rtld: Add glibc.rtld.enable_secure tunable. | expand |
Ping. Thanks, Joe On Fri, Jan 12, 2024 at 01:23:12PM -0500, Joe Simmons-Talbott wrote: > Add a tunable for setting __libc_enable_secure to 1. Do not set > __libc_enable_secure to 0 if the tunable is set to 0. Ignore all > tunables if glib.rtld.enable_secure is set. One use-case for this > addition is to enable testing code paths that depend on > __libc_enable_secure being set without the need to use setxid binaries. > --- > Changes to v4: > * Update copyright date to 2024 for new testcase. > > Changes to v3: > * Rebase and fix merge conflict in NEWS. > > Changes to v2: > * handle the tunable in __tunables_init so that it's done in a single > place. > * ignore all tunables if the tunable is set. > * update the testcase to only check the tunables if the enable_secure > tunable is not set. > * don't add tunables_strcmp as there is now already a version. > > Changes to v1: > * handle the tunable for the dynamic loader as well. > > NEWS | 5 ++ > elf/Makefile | 2 + > elf/dl-tunables.c | 11 +++ > elf/dl-tunables.list | 6 ++ > elf/tst-rtld-list-tunables.exp | 1 + > elf/tst-tunables-enable_secure.c | 126 +++++++++++++++++++++++++++++++ > 6 files changed, 151 insertions(+) > create mode 100644 elf/tst-tunables-enable_secure.c > > diff --git a/NEWS b/NEWS > index 83ae627f47..aff44f6d7f 100644 > --- a/NEWS > +++ b/NEWS > @@ -55,6 +55,11 @@ Major new features: > unsigned char, unsigned short, unsigned int, unsigned long int and > unsigned long long int, and a type-generic macro. > > +* A new tunable, glibc.rtld.enable_secure, used to run a program > + as if it were a setuid process, enabling a number of security features. This > + is currently a testing tool to allow more extensive verification tests for > + AT_SECURE programs and not meant to be a security feature. > + > Deprecated and removed features, and other changes affecting compatibility: > > * The ldconfig program now skips file names containing ';' or ending in > diff --git a/elf/Makefile b/elf/Makefile > index 5d78b659ce..45a6aa7a8d 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -285,6 +285,7 @@ tests-static-internal := \ > tst-tls1-static \ > tst-tls1-static-non-pie \ > tst-tunables \ > + tst-tunables-enable_secure \ > # tests-static-internal > > CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o > @@ -2676,6 +2677,7 @@ $(objpfx)tst-glibc-hwcaps-mask.out: \ > $(objpfx)tst-glibc-hwcaps-cache.out: $(objpfx)tst-glibc-hwcaps > > tst-tunables-ARGS = -- $(host-test-program-cmd) > +tst-tunables-enable_secure-ARGS = -- $(host-test-program-cmd) > > $(objpfx)list-tunables.out: tst-rtld-list-tunables.sh $(objpfx)ld.so > $(SHELL) $< $(objpfx)ld.so '$(test-wrapper-env)' \ > diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c > index 03e1a68675..d3ccd2ecd4 100644 > --- a/elf/dl-tunables.c > +++ b/elf/dl-tunables.c > @@ -223,6 +223,17 @@ parse_tunables_string (const char *valstring, struct tunable_toset_t *tunables) > { > tunables[ntunables++] = > (struct tunable_toset_t) { cur, value, p - value }; > + > + /* Ignore tunables if enable_secure is set */ > + if (tunable_is_name ("glibc.rtld.enable_secure", name)) > + { > + tunable_num_t val = (tunable_num_t) _dl_strtoul (value, NULL); > + if (val == 1) > + { > + __libc_enable_secure = 1; > + return 0; > + } > + } > break; > } > } > diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list > index 1b40407814..1186272c81 100644 > --- a/elf/dl-tunables.list > +++ b/elf/dl-tunables.list > @@ -136,6 +136,12 @@ glibc { > minval: 0 > default: 512 > } > + enable_secure { > + type: INT_32 > + minval: 0 > + maxval: 1 > + default: 0 > + } > } > > mem { > diff --git a/elf/tst-rtld-list-tunables.exp b/elf/tst-rtld-list-tunables.exp > index 2233ea9c7c..db0e1c86e9 100644 > --- a/elf/tst-rtld-list-tunables.exp > +++ b/elf/tst-rtld-list-tunables.exp > @@ -12,5 +12,6 @@ glibc.malloc.tcache_unsorted_limit: 0x0 (min: 0x0, max: 0x[f]+) > glibc.malloc.top_pad: 0x20000 (min: 0x0, max: 0x[f]+) > glibc.malloc.trim_threshold: 0x0 (min: 0x0, max: 0x[f]+) > glibc.rtld.dynamic_sort: 2 (min: 1, max: 2) > +glibc.rtld.enable_secure: 0 (min: 0, max: 1) > glibc.rtld.nns: 0x4 (min: 0x1, max: 0x10) > glibc.rtld.optional_static_tls: 0x200 (min: 0x0, max: 0x[f]+) > diff --git a/elf/tst-tunables-enable_secure.c b/elf/tst-tunables-enable_secure.c > new file mode 100644 > index 0000000000..e31e1f7faa > --- /dev/null > +++ b/elf/tst-tunables-enable_secure.c > @@ -0,0 +1,126 @@ > +/* Check GLIBC_TUNABLES parsing for enable_secure. > + Copyright (C) 2024 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 <array_length.h> > +#include <dl-tunables.h> > +#include <getopt.h> > +#include <intprops.h> > +#include <stdint.h> > +#include <stdlib.h> > +#include <support/capture_subprocess.h> > +#include <support/check.h> > +#include <sys/auxv.h> > +#include <unistd.h> > + > +static int restart; > +#define CMDLINE_OPTIONS \ > + { "restart", no_argument, &restart, 1 }, > + > +static const struct test_t > +{ > + const char *env; > + int32_t expected_malloc_check; > + int32_t expected_enable_secure; > +} tests[] = > +{ > + /* Expected tunable format. */ > + /* Tunables should be ignored if enable_secure is set. */ > + { > + "glibc.malloc.check=2:glibc.rtld.enable_secure=1", > + 0, > + 1, > + }, > + /* Tunables should be ignored if enable_secure is set. */ > + { > + "glibc.rtld.enable_secure=1:glibc.malloc.check=2", > + 0, > + 1, > + }, > + /* Tunables should be set if enable_secure is unset. */ > + { > + "glibc.rtld.enable_secure=0:glibc.malloc.check=2", > + 2, > + 0, > + }, > +}; > + > +static int > +handle_restart (int i) > +{ > + if (tests[i].expected_enable_secure == 1) > + { > + TEST_COMPARE (1, __libc_enable_secure); > + } > + else > + { > + TEST_COMPARE (tests[i].expected_malloc_check, > + TUNABLE_GET_FULL (glibc, malloc, check, int32_t, NULL)); > + TEST_COMPARE (tests[i].expected_enable_secure, > + TUNABLE_GET_FULL (glibc, rtld, enable_secure, int32_t, > + NULL)); > + } > + return 0; > +} > + > +static int > +do_test (int argc, char *argv[]) > +{ > + /* We must have either: > + - One or four parameters left if called initially: > + + path to ld.so optional > + + "--library-path" optional > + + the library path optional > + + the application name > + + the test to check */ > + > + TEST_VERIFY_EXIT (argc == 2 || argc == 5); > + > + if (restart) > + return handle_restart (atoi (argv[1])); > + > + char nteststr[INT_BUFSIZE_BOUND (int)]; > + > + char *spargv[10]; > + { > + int i = 0; > + for (; i < argc - 1; i++) > + spargv[i] = argv[i + 1]; > + spargv[i++] = (char *) "--direct"; > + spargv[i++] = (char *) "--restart"; > + spargv[i++] = nteststr; > + spargv[i] = NULL; > + } > + > + for (int i = 0; i < array_length (tests); i++) > + { > + snprintf (nteststr, sizeof nteststr, "%d", i); > + > + printf ("[%d] Spawned test for %s\n", i, tests[i].env); > + setenv ("GLIBC_TUNABLES", tests[i].env, 1); > + struct support_capture_subprocess result > + = support_capture_subprogram (spargv[0], spargv); > + support_capture_subprocess_check (&result, "tst-tunables-enable_secure", > + 0, sc_allow_stderr); > + support_capture_subprocess_free (&result); > + } > + > + return 0; > +} > + > +#define TEST_FUNCTION_ARGV do_test > +#include <support/test-driver.c> > -- > 2.41.0 >
On 2024-01-12 13:23, Joe Simmons-Talbott wrote: > Add a tunable for setting __libc_enable_secure to 1. Do not set > __libc_enable_secure to 0 if the tunable is set to 0. Ignore all > tunables if glib.rtld.enable_secure is set. One use-case for this > addition is to enable testing code paths that depend on > __libc_enable_secure being set without the need to use setxid binaries. Thanks for doing this! Please note the review comments below; there's a tiny nit in the NEWS file and some other notes. Please fix the nit and commit this and then send a [committed] email of the final patch to the list so that there's a record. The only thing missing here is a manual change documenting this tunable. Can you please send a follow-up patch for that? Thanks, Sid Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > --- > Changes to v4: > * Update copyright date to 2024 for new testcase. > > Changes to v3: > * Rebase and fix merge conflict in NEWS. > > Changes to v2: > * handle the tunable in __tunables_init so that it's done in a single > place. > * ignore all tunables if the tunable is set. > * update the testcase to only check the tunables if the enable_secure > tunable is not set. > * don't add tunables_strcmp as there is now already a version. > > Changes to v1: > * handle the tunable for the dynamic loader as well. > > NEWS | 5 ++ > elf/Makefile | 2 + > elf/dl-tunables.c | 11 +++ > elf/dl-tunables.list | 6 ++ > elf/tst-rtld-list-tunables.exp | 1 + > elf/tst-tunables-enable_secure.c | 126 +++++++++++++++++++++++++++++++ > 6 files changed, 151 insertions(+) > create mode 100644 elf/tst-tunables-enable_secure.c > > diff --git a/NEWS b/NEWS > index 83ae627f47..aff44f6d7f 100644 > --- a/NEWS > +++ b/NEWS > @@ -55,6 +55,11 @@ Major new features: > unsigned char, unsigned short, unsigned int, unsigned long int and > unsigned long long int, and a type-generic macro. > > +* A new tunable, glibc.rtld.enable_secure, used to run a program > + as if it were a setuid process, enabling a number of security features. This > + is currently a testing tool to allow more extensive verification tests for > + AT_SECURE programs and not meant to be a security feature. Maybe drop "enabling a number of security features", because it conflicts with "not meant to be a security feature"? > + > Deprecated and removed features, and other changes affecting compatibility: > > * The ldconfig program now skips file names containing ';' or ending in > diff --git a/elf/Makefile b/elf/Makefile > index 5d78b659ce..45a6aa7a8d 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -285,6 +285,7 @@ tests-static-internal := \ > tst-tls1-static \ > tst-tls1-static-non-pie \ > tst-tunables \ > + tst-tunables-enable_secure \ > # tests-static-internal > > CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o > @@ -2676,6 +2677,7 @@ $(objpfx)tst-glibc-hwcaps-mask.out: \ > $(objpfx)tst-glibc-hwcaps-cache.out: $(objpfx)tst-glibc-hwcaps > > tst-tunables-ARGS = -- $(host-test-program-cmd) > +tst-tunables-enable_secure-ARGS = -- $(host-test-program-cmd) > > $(objpfx)list-tunables.out: tst-rtld-list-tunables.sh $(objpfx)ld.so > $(SHELL) $< $(objpfx)ld.so '$(test-wrapper-env)' \ > diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c > index 03e1a68675..d3ccd2ecd4 100644 > --- a/elf/dl-tunables.c > +++ b/elf/dl-tunables.c > @@ -223,6 +223,17 @@ parse_tunables_string (const char *valstring, struct tunable_toset_t *tunables) > { > tunables[ntunables++] = > (struct tunable_toset_t) { cur, value, p - value }; > + > + /* Ignore tunables if enable_secure is set */ > + if (tunable_is_name ("glibc.rtld.enable_secure", name)) > + { > + tunable_num_t val = (tunable_num_t) _dl_strtoul (value, NULL); > + if (val == 1) > + { > + __libc_enable_secure = 1; > + return 0; > + } > + } Enable sxid and ignore all tunables. It never disables __libc_enable_secure because we never come here if it's enabled. OK. This detail should get mentioned in the manual so that we hold ourselves to that standard. > break; > } > } > diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list > index 1b40407814..1186272c81 100644 > --- a/elf/dl-tunables.list > +++ b/elf/dl-tunables.list > @@ -136,6 +136,12 @@ glibc { > minval: 0 > default: 512 > } > + enable_secure { > + type: INT_32 > + minval: 0 > + maxval: 1 > + default: 0 > + } > } > > mem { > diff --git a/elf/tst-rtld-list-tunables.exp b/elf/tst-rtld-list-tunables.exp > index 2233ea9c7c..db0e1c86e9 100644 > --- a/elf/tst-rtld-list-tunables.exp > +++ b/elf/tst-rtld-list-tunables.exp > @@ -12,5 +12,6 @@ glibc.malloc.tcache_unsorted_limit: 0x0 (min: 0x0, max: 0x[f]+) > glibc.malloc.top_pad: 0x20000 (min: 0x0, max: 0x[f]+) > glibc.malloc.trim_threshold: 0x0 (min: 0x0, max: 0x[f]+) > glibc.rtld.dynamic_sort: 2 (min: 1, max: 2) > +glibc.rtld.enable_secure: 0 (min: 0, max: 1) > glibc.rtld.nns: 0x4 (min: 0x1, max: 0x10) > glibc.rtld.optional_static_tls: 0x200 (min: 0x0, max: 0x[f]+) > diff --git a/elf/tst-tunables-enable_secure.c b/elf/tst-tunables-enable_secure.c > new file mode 100644 > index 0000000000..e31e1f7faa > --- /dev/null > +++ b/elf/tst-tunables-enable_secure.c > @@ -0,0 +1,126 @@ > +/* Check GLIBC_TUNABLES parsing for enable_secure. > + Copyright (C) 2024 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 <array_length.h> > +#include <dl-tunables.h> > +#include <getopt.h> > +#include <intprops.h> > +#include <stdint.h> > +#include <stdlib.h> > +#include <support/capture_subprocess.h> > +#include <support/check.h> > +#include <sys/auxv.h> > +#include <unistd.h> > + > +static int restart; > +#define CMDLINE_OPTIONS \ > + { "restart", no_argument, &restart, 1 }, > + > +static const struct test_t > +{ > + const char *env; > + int32_t expected_malloc_check; > + int32_t expected_enable_secure; > +} tests[] = > +{ > + /* Expected tunable format. */ > + /* Tunables should be ignored if enable_secure is set. */ > + { > + "glibc.malloc.check=2:glibc.rtld.enable_secure=1", > + 0, > + 1, > + }, > + /* Tunables should be ignored if enable_secure is set. */ > + { > + "glibc.rtld.enable_secure=1:glibc.malloc.check=2", > + 0, > + 1, > + }, > + /* Tunables should be set if enable_secure is unset. */ > + { > + "glibc.rtld.enable_secure=0:glibc.malloc.check=2", > + 2, > + 0, > + }, > +}; > + > +static int > +handle_restart (int i) > +{ > + if (tests[i].expected_enable_secure == 1) > + { > + TEST_COMPARE (1, __libc_enable_secure); > + } > + else > + { > + TEST_COMPARE (tests[i].expected_malloc_check, > + TUNABLE_GET_FULL (glibc, malloc, check, int32_t, NULL)); > + TEST_COMPARE (tests[i].expected_enable_secure, > + TUNABLE_GET_FULL (glibc, rtld, enable_secure, int32_t, > + NULL)); > + } > + return 0; > +} > + > +static int > +do_test (int argc, char *argv[]) > +{ > + /* We must have either: > + - One or four parameters left if called initially: > + + path to ld.so optional > + + "--library-path" optional > + + the library path optional > + + the application name > + + the test to check */ > + > + TEST_VERIFY_EXIT (argc == 2 || argc == 5); > + > + if (restart) > + return handle_restart (atoi (argv[1])); > + > + char nteststr[INT_BUFSIZE_BOUND (int)]; > + > + char *spargv[10]; > + { > + int i = 0; > + for (; i < argc - 1; i++) > + spargv[i] = argv[i + 1]; > + spargv[i++] = (char *) "--direct"; > + spargv[i++] = (char *) "--restart"; > + spargv[i++] = nteststr; > + spargv[i] = NULL; > + } > + > + for (int i = 0; i < array_length (tests); i++) > + { > + snprintf (nteststr, sizeof nteststr, "%d", i); > + > + printf ("[%d] Spawned test for %s\n", i, tests[i].env); > + setenv ("GLIBC_TUNABLES", tests[i].env, 1); > + struct support_capture_subprocess result > + = support_capture_subprogram (spargv[0], spargv); > + support_capture_subprocess_check (&result, "tst-tunables-enable_secure", > + 0, sc_allow_stderr); > + support_capture_subprocess_free (&result); > + } > + > + return 0; > +} > + > +#define TEST_FUNCTION_ARGV do_test > +#include <support/test-driver.c>
On Thu, Feb 29, 2024 at 9:44 AM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote: > > On 2024-01-12 13:23, Joe Simmons-Talbott wrote: > > Add a tunable for setting __libc_enable_secure to 1. Do not set > > __libc_enable_secure to 0 if the tunable is set to 0. Ignore all > > tunables if glib.rtld.enable_secure is set. One use-case for this > > addition is to enable testing code paths that depend on > > __libc_enable_secure being set without the need to use setxid binaries. > > Thanks for doing this! Please note the review comments below; there's a > tiny nit in the NEWS file and some other notes. Please fix the nit and > commit this and then send a [committed] email of the final patch to the > list so that there's a record. Thanks for the review. I've done this. As well as posting a follow-up patch to move the NEWS entry from the 2.39 section to the 2.40 section. > > The only thing missing here is a manual change documenting this tunable. > Can you please send a follow-up patch for that? I've posted a follow-up patch documenting the tunable in the manual as well. Thanks, Joe > > Thanks, > Sid > > Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> > > > --- > > Changes to v4: > > * Update copyright date to 2024 for new testcase. > > > > Changes to v3: > > * Rebase and fix merge conflict in NEWS. > > > > Changes to v2: > > * handle the tunable in __tunables_init so that it's done in a single > > place. > > * ignore all tunables if the tunable is set. > > * update the testcase to only check the tunables if the enable_secure > > tunable is not set. > > * don't add tunables_strcmp as there is now already a version. > > > > Changes to v1: > > * handle the tunable for the dynamic loader as well. > > > > NEWS | 5 ++ > > elf/Makefile | 2 + > > elf/dl-tunables.c | 11 +++ > > elf/dl-tunables.list | 6 ++ > > elf/tst-rtld-list-tunables.exp | 1 + > > elf/tst-tunables-enable_secure.c | 126 +++++++++++++++++++++++++++++++ > > 6 files changed, 151 insertions(+) > > create mode 100644 elf/tst-tunables-enable_secure.c > > > > diff --git a/NEWS b/NEWS > > index 83ae627f47..aff44f6d7f 100644 > > --- a/NEWS > > +++ b/NEWS > > @@ -55,6 +55,11 @@ Major new features: > > unsigned char, unsigned short, unsigned int, unsigned long int and > > unsigned long long int, and a type-generic macro. > > > > +* A new tunable, glibc.rtld.enable_secure, used to run a program > > + as if it were a setuid process, enabling a number of security features. This > > + is currently a testing tool to allow more extensive verification tests for > > + AT_SECURE programs and not meant to be a security feature. > > Maybe drop "enabling a number of security features", because it > conflicts with "not meant to be a security feature"? > > > + > > Deprecated and removed features, and other changes affecting compatibility: > > > > * The ldconfig program now skips file names containing ';' or ending in > > diff --git a/elf/Makefile b/elf/Makefile > > index 5d78b659ce..45a6aa7a8d 100644 > > --- a/elf/Makefile > > +++ b/elf/Makefile > > @@ -285,6 +285,7 @@ tests-static-internal := \ > > tst-tls1-static \ > > tst-tls1-static-non-pie \ > > tst-tunables \ > > + tst-tunables-enable_secure \ > > # tests-static-internal > > > > CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o > > @@ -2676,6 +2677,7 @@ $(objpfx)tst-glibc-hwcaps-mask.out: \ > > $(objpfx)tst-glibc-hwcaps-cache.out: $(objpfx)tst-glibc-hwcaps > > > > tst-tunables-ARGS = -- $(host-test-program-cmd) > > +tst-tunables-enable_secure-ARGS = -- $(host-test-program-cmd) > > > > $(objpfx)list-tunables.out: tst-rtld-list-tunables.sh $(objpfx)ld.so > > $(SHELL) $< $(objpfx)ld.so '$(test-wrapper-env)' \ > > diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c > > index 03e1a68675..d3ccd2ecd4 100644 > > --- a/elf/dl-tunables.c > > +++ b/elf/dl-tunables.c > > @@ -223,6 +223,17 @@ parse_tunables_string (const char *valstring, struct tunable_toset_t *tunables) > > { > > tunables[ntunables++] = > > (struct tunable_toset_t) { cur, value, p - value }; > > + > > + /* Ignore tunables if enable_secure is set */ > > + if (tunable_is_name ("glibc.rtld.enable_secure", name)) > > + { > > + tunable_num_t val = (tunable_num_t) _dl_strtoul (value, NULL); > > + if (val == 1) > > + { > > + __libc_enable_secure = 1; > > + return 0; > > + } > > + } > > Enable sxid and ignore all tunables. It never disables > __libc_enable_secure because we never come here if it's enabled. OK. > This detail should get mentioned in the manual so that we hold ourselves > to that standard. > > > break; > > } > > } > > diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list > > index 1b40407814..1186272c81 100644 > > --- a/elf/dl-tunables.list > > +++ b/elf/dl-tunables.list > > @@ -136,6 +136,12 @@ glibc { > > minval: 0 > > default: 512 > > } > > + enable_secure { > > + type: INT_32 > > + minval: 0 > > + maxval: 1 > > + default: 0 > > + } > > } > > > > mem { > > diff --git a/elf/tst-rtld-list-tunables.exp b/elf/tst-rtld-list-tunables.exp > > index 2233ea9c7c..db0e1c86e9 100644 > > --- a/elf/tst-rtld-list-tunables.exp > > +++ b/elf/tst-rtld-list-tunables.exp > > @@ -12,5 +12,6 @@ glibc.malloc.tcache_unsorted_limit: 0x0 (min: 0x0, max: 0x[f]+) > > glibc.malloc.top_pad: 0x20000 (min: 0x0, max: 0x[f]+) > > glibc.malloc.trim_threshold: 0x0 (min: 0x0, max: 0x[f]+) > > glibc.rtld.dynamic_sort: 2 (min: 1, max: 2) > > +glibc.rtld.enable_secure: 0 (min: 0, max: 1) > > glibc.rtld.nns: 0x4 (min: 0x1, max: 0x10) > > glibc.rtld.optional_static_tls: 0x200 (min: 0x0, max: 0x[f]+) > > diff --git a/elf/tst-tunables-enable_secure.c b/elf/tst-tunables-enable_secure.c > > new file mode 100644 > > index 0000000000..e31e1f7faa > > --- /dev/null > > +++ b/elf/tst-tunables-enable_secure.c > > @@ -0,0 +1,126 @@ > > +/* Check GLIBC_TUNABLES parsing for enable_secure. > > + Copyright (C) 2024 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 <array_length.h> > > +#include <dl-tunables.h> > > +#include <getopt.h> > > +#include <intprops.h> > > +#include <stdint.h> > > +#include <stdlib.h> > > +#include <support/capture_subprocess.h> > > +#include <support/check.h> > > +#include <sys/auxv.h> > > +#include <unistd.h> > > + > > +static int restart; > > +#define CMDLINE_OPTIONS \ > > + { "restart", no_argument, &restart, 1 }, > > + > > +static const struct test_t > > +{ > > + const char *env; > > + int32_t expected_malloc_check; > > + int32_t expected_enable_secure; > > +} tests[] = > > +{ > > + /* Expected tunable format. */ > > + /* Tunables should be ignored if enable_secure is set. */ > > + { > > + "glibc.malloc.check=2:glibc.rtld.enable_secure=1", > > + 0, > > + 1, > > + }, > > + /* Tunables should be ignored if enable_secure is set. */ > > + { > > + "glibc.rtld.enable_secure=1:glibc.malloc.check=2", > > + 0, > > + 1, > > + }, > > + /* Tunables should be set if enable_secure is unset. */ > > + { > > + "glibc.rtld.enable_secure=0:glibc.malloc.check=2", > > + 2, > > + 0, > > + }, > > +}; > > + > > +static int > > +handle_restart (int i) > > +{ > > + if (tests[i].expected_enable_secure == 1) > > + { > > + TEST_COMPARE (1, __libc_enable_secure); > > + } > > + else > > + { > > + TEST_COMPARE (tests[i].expected_malloc_check, > > + TUNABLE_GET_FULL (glibc, malloc, check, int32_t, NULL)); > > + TEST_COMPARE (tests[i].expected_enable_secure, > > + TUNABLE_GET_FULL (glibc, rtld, enable_secure, int32_t, > > + NULL)); > > + } > > + return 0; > > +} > > + > > +static int > > +do_test (int argc, char *argv[]) > > +{ > > + /* We must have either: > > + - One or four parameters left if called initially: > > + + path to ld.so optional > > + + "--library-path" optional > > + + the library path optional > > + + the application name > > + + the test to check */ > > + > > + TEST_VERIFY_EXIT (argc == 2 || argc == 5); > > + > > + if (restart) > > + return handle_restart (atoi (argv[1])); > > + > > + char nteststr[INT_BUFSIZE_BOUND (int)]; > > + > > + char *spargv[10]; > > + { > > + int i = 0; > > + for (; i < argc - 1; i++) > > + spargv[i] = argv[i + 1]; > > + spargv[i++] = (char *) "--direct"; > > + spargv[i++] = (char *) "--restart"; > > + spargv[i++] = nteststr; > > + spargv[i] = NULL; > > + } > > + > > + for (int i = 0; i < array_length (tests); i++) > > + { > > + snprintf (nteststr, sizeof nteststr, "%d", i); > > + > > + printf ("[%d] Spawned test for %s\n", i, tests[i].env); > > + setenv ("GLIBC_TUNABLES", tests[i].env, 1); > > + struct support_capture_subprocess result > > + = support_capture_subprogram (spargv[0], spargv); > > + support_capture_subprocess_check (&result, "tst-tunables-enable_secure", > > + 0, sc_allow_stderr); > > + support_capture_subprocess_free (&result); > > + } > > + > > + return 0; > > +} > > + > > +#define TEST_FUNCTION_ARGV do_test > > +#include <support/test-driver.c> >
diff --git a/NEWS b/NEWS index 83ae627f47..aff44f6d7f 100644 --- a/NEWS +++ b/NEWS @@ -55,6 +55,11 @@ Major new features: unsigned char, unsigned short, unsigned int, unsigned long int and unsigned long long int, and a type-generic macro. +* A new tunable, glibc.rtld.enable_secure, used to run a program + as if it were a setuid process, enabling a number of security features. This + is currently a testing tool to allow more extensive verification tests for + AT_SECURE programs and not meant to be a security feature. + Deprecated and removed features, and other changes affecting compatibility: * The ldconfig program now skips file names containing ';' or ending in diff --git a/elf/Makefile b/elf/Makefile index 5d78b659ce..45a6aa7a8d 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -285,6 +285,7 @@ tests-static-internal := \ tst-tls1-static \ tst-tls1-static-non-pie \ tst-tunables \ + tst-tunables-enable_secure \ # tests-static-internal CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o @@ -2676,6 +2677,7 @@ $(objpfx)tst-glibc-hwcaps-mask.out: \ $(objpfx)tst-glibc-hwcaps-cache.out: $(objpfx)tst-glibc-hwcaps tst-tunables-ARGS = -- $(host-test-program-cmd) +tst-tunables-enable_secure-ARGS = -- $(host-test-program-cmd) $(objpfx)list-tunables.out: tst-rtld-list-tunables.sh $(objpfx)ld.so $(SHELL) $< $(objpfx)ld.so '$(test-wrapper-env)' \ diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index 03e1a68675..d3ccd2ecd4 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -223,6 +223,17 @@ parse_tunables_string (const char *valstring, struct tunable_toset_t *tunables) { tunables[ntunables++] = (struct tunable_toset_t) { cur, value, p - value }; + + /* Ignore tunables if enable_secure is set */ + if (tunable_is_name ("glibc.rtld.enable_secure", name)) + { + tunable_num_t val = (tunable_num_t) _dl_strtoul (value, NULL); + if (val == 1) + { + __libc_enable_secure = 1; + return 0; + } + } break; } } diff --git a/elf/dl-tunables.list b/elf/dl-tunables.list index 1b40407814..1186272c81 100644 --- a/elf/dl-tunables.list +++ b/elf/dl-tunables.list @@ -136,6 +136,12 @@ glibc { minval: 0 default: 512 } + enable_secure { + type: INT_32 + minval: 0 + maxval: 1 + default: 0 + } } mem { diff --git a/elf/tst-rtld-list-tunables.exp b/elf/tst-rtld-list-tunables.exp index 2233ea9c7c..db0e1c86e9 100644 --- a/elf/tst-rtld-list-tunables.exp +++ b/elf/tst-rtld-list-tunables.exp @@ -12,5 +12,6 @@ glibc.malloc.tcache_unsorted_limit: 0x0 (min: 0x0, max: 0x[f]+) glibc.malloc.top_pad: 0x20000 (min: 0x0, max: 0x[f]+) glibc.malloc.trim_threshold: 0x0 (min: 0x0, max: 0x[f]+) glibc.rtld.dynamic_sort: 2 (min: 1, max: 2) +glibc.rtld.enable_secure: 0 (min: 0, max: 1) glibc.rtld.nns: 0x4 (min: 0x1, max: 0x10) glibc.rtld.optional_static_tls: 0x200 (min: 0x0, max: 0x[f]+) diff --git a/elf/tst-tunables-enable_secure.c b/elf/tst-tunables-enable_secure.c new file mode 100644 index 0000000000..e31e1f7faa --- /dev/null +++ b/elf/tst-tunables-enable_secure.c @@ -0,0 +1,126 @@ +/* Check GLIBC_TUNABLES parsing for enable_secure. + Copyright (C) 2024 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 <array_length.h> +#include <dl-tunables.h> +#include <getopt.h> +#include <intprops.h> +#include <stdint.h> +#include <stdlib.h> +#include <support/capture_subprocess.h> +#include <support/check.h> +#include <sys/auxv.h> +#include <unistd.h> + +static int restart; +#define CMDLINE_OPTIONS \ + { "restart", no_argument, &restart, 1 }, + +static const struct test_t +{ + const char *env; + int32_t expected_malloc_check; + int32_t expected_enable_secure; +} tests[] = +{ + /* Expected tunable format. */ + /* Tunables should be ignored if enable_secure is set. */ + { + "glibc.malloc.check=2:glibc.rtld.enable_secure=1", + 0, + 1, + }, + /* Tunables should be ignored if enable_secure is set. */ + { + "glibc.rtld.enable_secure=1:glibc.malloc.check=2", + 0, + 1, + }, + /* Tunables should be set if enable_secure is unset. */ + { + "glibc.rtld.enable_secure=0:glibc.malloc.check=2", + 2, + 0, + }, +}; + +static int +handle_restart (int i) +{ + if (tests[i].expected_enable_secure == 1) + { + TEST_COMPARE (1, __libc_enable_secure); + } + else + { + TEST_COMPARE (tests[i].expected_malloc_check, + TUNABLE_GET_FULL (glibc, malloc, check, int32_t, NULL)); + TEST_COMPARE (tests[i].expected_enable_secure, + TUNABLE_GET_FULL (glibc, rtld, enable_secure, int32_t, + NULL)); + } + return 0; +} + +static int +do_test (int argc, char *argv[]) +{ + /* We must have either: + - One or four parameters left if called initially: + + path to ld.so optional + + "--library-path" optional + + the library path optional + + the application name + + the test to check */ + + TEST_VERIFY_EXIT (argc == 2 || argc == 5); + + if (restart) + return handle_restart (atoi (argv[1])); + + char nteststr[INT_BUFSIZE_BOUND (int)]; + + char *spargv[10]; + { + int i = 0; + for (; i < argc - 1; i++) + spargv[i] = argv[i + 1]; + spargv[i++] = (char *) "--direct"; + spargv[i++] = (char *) "--restart"; + spargv[i++] = nteststr; + spargv[i] = NULL; + } + + for (int i = 0; i < array_length (tests); i++) + { + snprintf (nteststr, sizeof nteststr, "%d", i); + + printf ("[%d] Spawned test for %s\n", i, tests[i].env); + setenv ("GLIBC_TUNABLES", tests[i].env, 1); + struct support_capture_subprocess result + = support_capture_subprogram (spargv[0], spargv); + support_capture_subprocess_check (&result, "tst-tunables-enable_secure", + 0, sc_allow_stderr); + support_capture_subprocess_free (&result); + } + + return 0; +} + +#define TEST_FUNCTION_ARGV do_test +#include <support/test-driver.c>