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Merge pull request #26935 from keszybz/test-parse_aux

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Add test for auxv parsing
This commit is contained in:
Luca Boccassi
2023-03-23 23:13:42 +00:00
committed by GitHub
parent d024c4d0e1 f39546a881
commit 2a775d5faf
17 changed files with 228 additions and 126 deletions
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src/coredump/coredump.c
+5 -69
View File
@@ -49,7 +49,6 @@
#include "sync-util.h"
#include "tmpfile-util.h"
#include "uid-alloc-range.h"
#include "unaligned.h"
#include "user-util.h"
/* The maximum size up to which we process coredumps. We use 1G on 32bit systems, and 32G on 64bit systems */
@@ -336,66 +335,6 @@ static int make_filename(const Context *context, char **ret) {
return 0;
}
#define _DEFINE_PARSE_AUXV(size, type, unaligned_read) \
static int parse_auxv##size( \
const void *auxv, \
size_t size_bytes, \
int *at_secure, \
uid_t *uid, \
uid_t *euid, \
gid_t *gid, \
gid_t *egid) { \
\
assert(auxv || size_bytes == 0); \
\
if (size_bytes % (2 * sizeof(type)) != 0) \
return log_warning_errno(SYNTHETIC_ERRNO(EIO), \
"Incomplete auxv structure (%zu bytes).", \
size_bytes); \
\
size_t words = size_bytes / sizeof(type); \
\
/* Note that we set output variables even on error. */ \
\
for (size_t i = 0; i + 1 < words; i += 2) { \
type key, val; \
\
key = unaligned_read((uint8_t*) auxv + i * sizeof(type)); \
val = unaligned_read((uint8_t*) auxv + (i + 1) * sizeof(type)); \
\
switch (key) { \
case AT_SECURE: \
*at_secure = val != 0; \
break; \
case AT_UID: \
*uid = val; \
break; \
case AT_EUID: \
*euid = val; \
break; \
case AT_GID: \
*gid = val; \
break; \
case AT_EGID: \
*egid = val; \
break; \
case AT_NULL: \
if (val != 0) \
goto error; \
return 0; \
} \
} \
error: \
return log_warning_errno(SYNTHETIC_ERRNO(ENODATA), \
"AT_NULL terminator not found, cannot parse auxv structure."); \
}
#define DEFINE_PARSE_AUXV(size)\
_DEFINE_PARSE_AUXV(size, uint##size##_t, unaligned_read_ne##size)
DEFINE_PARSE_AUXV(32);
DEFINE_PARSE_AUXV(64);
static int grant_user_access(int core_fd, const Context *context) {
int at_secure = -1;
uid_t uid = UID_INVALID, euid = UID_INVALID;
@@ -430,14 +369,11 @@ static int grant_user_access(int core_fd, const Context *context) {
return log_info_errno(SYNTHETIC_ERRNO(EUCLEAN),
"Core file has non-native endianness, not adjusting permissions.");
if (elf[EI_CLASS] == ELFCLASS64)
r = parse_auxv64(context->meta[META_PROC_AUXV],
context->meta_size[META_PROC_AUXV],
&at_secure, &uid, &euid, &gid, &egid);
else
r = parse_auxv32(context->meta[META_PROC_AUXV],
context->meta_size[META_PROC_AUXV],
&at_secure, &uid, &euid, &gid, &egid);
r = parse_auxv(LOG_WARNING,
/* elf_class= */ elf[EI_CLASS],
context->meta[META_PROC_AUXV],
context->meta_size[META_PROC_AUXV],
&at_secure, &uid, &euid, &gid, &egid);
if (r < 0)
return r;
src/shared/coredump-util.c
+92
View File
@@ -1,9 +1,12 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <elf.h>
#include "coredump-util.h"
#include "extract-word.h"
#include "fileio.h"
#include "string-table.h"
#include "unaligned.h"
#include "virt.h"
static const char *const coredump_filter_table[_COREDUMP_FILTER_MAX] = {
@@ -65,6 +68,95 @@ int coredump_filter_mask_from_string(const char *s, uint64_t *ret) {
return 0;
}
#define _DEFINE_PARSE_AUXV(size, type, unaligned_read) \
static int parse_auxv##size( \
int log_level, \
const void *auxv, \
size_t size_bytes, \
int *at_secure, \
uid_t *uid, \
uid_t *euid, \
gid_t *gid, \
gid_t *egid) { \
\
assert(auxv || size_bytes == 0); \
assert(at_secure); \
assert(uid); \
assert(euid); \
assert(gid); \
assert(egid); \
\
if (size_bytes % (2 * sizeof(type)) != 0) \
return log_full_errno(log_level, \
SYNTHETIC_ERRNO(EIO), \
"Incomplete auxv structure (%zu bytes).", \
size_bytes); \
\
size_t words = size_bytes / sizeof(type); \
\
/* Note that we set output variables even on error. */ \
\
for (size_t i = 0; i + 1 < words; i += 2) { \
type key, val; \
\
key = unaligned_read((uint8_t*) auxv + i * sizeof(type)); \
val = unaligned_read((uint8_t*) auxv + (i + 1) * sizeof(type)); \
\
switch (key) { \
case AT_SECURE: \
*at_secure = val != 0; \
break; \
case AT_UID: \
*uid = val; \
break; \
case AT_EUID: \
*euid = val; \
break; \
case AT_GID: \
*gid = val; \
break; \
case AT_EGID: \
*egid = val; \
break; \
case AT_NULL: \
if (val != 0) \
goto error; \
return 0; \
} \
} \
error: \
return log_full_errno(log_level, \
SYNTHETIC_ERRNO(ENODATA), \
"AT_NULL terminator not found, cannot parse auxv structure."); \
}
#define DEFINE_PARSE_AUXV(size) \
_DEFINE_PARSE_AUXV(size, uint##size##_t, unaligned_read_ne##size)
DEFINE_PARSE_AUXV(32);
DEFINE_PARSE_AUXV(64);
int parse_auxv(int log_level,
uint8_t elf_class,
const void *auxv,
size_t size_bytes,
int *at_secure,
uid_t *uid,
uid_t *euid,
gid_t *gid,
gid_t *egid) {
switch (elf_class) {
case ELFCLASS64:
return parse_auxv64(log_level, auxv, size_bytes, at_secure, uid, euid, gid, egid);
case ELFCLASS32:
return parse_auxv32(log_level, auxv, size_bytes, at_secure, uid, euid, gid, egid);
default:
return log_full_errno(log_level, SYNTHETIC_ERRNO(EPROTONOSUPPORT),
"Unknown ELF class %d.", elf_class);
}
}
int set_coredump_filter(uint64_t value) {
char t[STRLEN("0xFFFFFFFF")];
src/shared/coredump-util.h
+10
View File
@@ -26,5 +26,15 @@ const char* coredump_filter_to_string(CoredumpFilter i) _const_;
CoredumpFilter coredump_filter_from_string(const char *s) _pure_;
int coredump_filter_mask_from_string(const char *s, uint64_t *ret);
int parse_auxv(int log_level,
uint8_t elf_class,
const void *auxv,
size_t size_bytes,
int *at_secure,
uid_t *uid,
uid_t *euid,
gid_t *gid,
gid_t *egid);
int set_coredump_filter(uint64_t value);
void disable_coredumps(void);
src/test/test-coredump-util.c
+92
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@@ -1,7 +1,12 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <elf.h>
#include "alloc-util.h"
#include "coredump-util.h"
#include "fileio.h"
#include "fd-util.h"
#include "format-util.h"
#include "macro.h"
#include "tests.h"
@@ -64,4 +69,91 @@ TEST(coredump_filter_mask_from_string) {
1 << COREDUMP_FILTER_SHARED_DAX)));
}
static void test_parse_auxv_two(
uint8_t elf_class,
size_t offset,
const char *data,
size_t data_size,
int expect_at_secure,
uid_t expect_uid,
uid_t expect_euid,
gid_t expect_gid,
gid_t expect_egid) {
int at_secure;
uid_t uid, euid;
gid_t gid, egid;
assert_se(parse_auxv(LOG_ERR, elf_class, data, data_size,
&at_secure, &uid, &euid, &gid, &egid) == 0);
log_debug("[offset=%zu] at_secure=%d, uid="UID_FMT", euid="UID_FMT", gid="GID_FMT", egid="GID_FMT,
offset,
at_secure, uid, euid, gid, egid);
assert_se(uid == expect_uid);
assert_se(euid == expect_euid);
assert_se(gid == expect_gid);
assert_se(egid == expect_egid);
}
static void test_parse_auxv_one(
uint8_t elf_class,
int dir_fd,
const char *filename,
int expect_at_secure,
uid_t expect_uid,
uid_t expect_euid,
gid_t expect_gid,
gid_t expect_egid) {
_cleanup_free_ char *buf;
const char *data;
size_t data_size;
log_info("Parsing %s…", filename);
assert_se(read_full_file_at(dir_fd, filename, &buf, &data_size) >= 0);
for (size_t offset = 0; offset < 8; offset++) {
_cleanup_free_ char *buf2 = NULL;
if (offset == 0)
data = buf;
else {
assert_se(buf2 = malloc(offset + data_size));
memcpy(buf2 + offset, buf, data_size);
data = buf2 + offset;
}
test_parse_auxv_two(elf_class, offset, data, data_size,
expect_at_secure, expect_uid, expect_euid, expect_gid, expect_egid);
}
}
TEST(test_parse_auxv) {
_cleanup_free_ char *dir = NULL;
_cleanup_close_ int dir_fd = -EBADF;
assert_se(get_testdata_dir("auxv", &dir) >= 0);
dir_fd = open(dir, O_RDONLY | O_CLOEXEC | O_DIRECTORY | O_PATH);
assert_se(dir_fd >= 0);
if (__BYTE_ORDER == __LITTLE_ENDIAN) {
test_parse_auxv_one(ELFCLASS32, dir_fd, "resolved.arm32", 0, 193, 193, 193, 193);
test_parse_auxv_one(ELFCLASS64, dir_fd, "bash.riscv64", 0, 1001, 1001, 1001, 1001);
test_parse_auxv_one(ELFCLASS32, dir_fd, "sleep.i686", 0, 1000, 1000, 1000, 1000);
/* after chgrp and chmod g+s */
test_parse_auxv_one(ELFCLASS32, dir_fd, "sleep32.i686", 1, 1000, 1000, 1000, 10);
test_parse_auxv_one(ELFCLASS64, dir_fd, "sleep64.amd64", 1, 1000, 1000, 1000, 10);
test_parse_auxv_one(ELFCLASS64, dir_fd, "sudo.aarch64", 1, 1494200408, 0, 1494200408, 1494200408);
test_parse_auxv_one(ELFCLASS64, dir_fd, "sudo.amd64", 1, 1000, 0, 1000, 1000);
/* Those run unprivileged, but start as root. */
test_parse_auxv_one(ELFCLASS64, dir_fd, "dbus-broker-launch.amd64", 0, 0, 0, 0, 0);
test_parse_auxv_one(ELFCLASS64, dir_fd, "dbus-broker-launch.aarch64", 0, 0, 0, 0, 0);
test_parse_auxv_one(ELFCLASS64, dir_fd, "polkitd.aarch64", 0, 0, 0, 0, 0);
} else {
test_parse_auxv_one(ELFCLASS64, dir_fd, "cat.s390x", 0, 3481, 3481, 3481, 3481);
}
}
DEFINE_TEST_MAIN(LOG_INFO);
test/auxv/.gitattributes
+3
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@@ -0,0 +1,3 @@
/*.* -whitespace
/*.* binary
/*.* generated
test/auxv/bash.riscv64
BIN
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Binary file not shown.
test/auxv/cat.s390x
BIN
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Binary file not shown.
test/auxv/dbus-broker-launch.aarch64
BIN
View File
Binary file not shown.
test/auxv/dbus-broker-launch.amd64
BIN
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Binary file not shown.
test/auxv/polkitd.aarch64
BIN
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Binary file not shown.
test/auxv/resolved.arm32
BIN
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Binary file not shown.
test/auxv/sleep.i686
BIN
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Binary file not shown.
test/auxv/sleep32.i686
BIN
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Binary file not shown.
test/auxv/sleep64.amd64
BIN
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Binary file not shown.
test/auxv/sudo.aarch64
BIN
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Binary file not shown.
test/auxv/sudo.amd64
BIN
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Binary file not shown.
test/meson.build
+26 -57
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@@ -3,63 +3,32 @@
if install_tests
testdata_dir = testsdir + '/testdata/'
install_subdir('journal-data',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('test-execute',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('test-fstab-generator',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('test-path',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('test-path-util',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('test-umount',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('test-network-generator-conversion',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-03.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-04.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-06.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-10.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-11.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-16.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-28.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-30.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-52.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-63.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
install_subdir('testsuite-80.units',
exclude_files : '.gitattributes',
install_dir : testdata_dir)
foreach subdir : [
'auxv',
'journal-data',
'units',
'test-execute',
'test-fstab-generator',
'test-path',
'test-path-util',
'test-umount',
'test-network-generator-conversion',
'testsuite-03.units',
'testsuite-04.units',
'testsuite-06.units',
'testsuite-10.units',
'testsuite-11.units',
'testsuite-16.units',
'testsuite-28.units',
'testsuite-30.units',
'testsuite-52.units',
'testsuite-63.units',
'testsuite-80.units',
]
install_subdir(subdir,
exclude_files : '.gitattributes',
install_dir : testdata_dir)
endforeach
install_data(kbd_model_map,
install_dir : testdata_dir + '/test-keymap-util')