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Merge pull request #16424 from keszybz/cap-bpf-compat 

Handle new capabilities gracefully
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2020-07-11 13:35:34 +02:00 committed by GitHub
parent b0ff0eaa01 5700780389
commit b159831b61
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 30 additions and 37 deletions
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17
src/basic/cap-list.c
View File

@ -9,6 +9,7 @@
#include "extract-word.h"
#include "macro.h"
#include "parse-util.h"
#include "stdio-util.h"
#include "util.h"
static const struct capability_name* lookup_capability(register const char *str, register GPERF_LEN_TYPE len);
@ -17,7 +18,6 @@ static const struct capability_name* lookup_capability(register const char *str,
#include "cap-to-name.h"
const char *capability_to_name(int id) {
if (id < 0)
return NULL;
@ -36,7 +36,7 @@ int capability_from_name(const char *name) {
/* Try to parse numeric capability */
r = safe_atoi(name, &i);
if (r >= 0) {
if (i >= 0 && (size_t) i < ELEMENTSOF(capability_names))
if (i >= 0 && i < 64)
return i;
else
return -EINVAL;
@ -56,19 +56,21 @@ int capability_list_length(void) {
int capability_set_to_string_alloc(uint64_t set, char **s) {
_cleanup_free_ char *str = NULL;
unsigned long i;
size_t allocated = 0, n = 0;
assert(s);
for (i = 0; i <= cap_last_cap(); i++)
for (unsigned i = 0; i <= cap_last_cap(); i++)
if (set & (UINT64_C(1) << i)) {
const char *p;
char buf[2 + 16 + 1];
size_t add;
p = capability_to_name(i);
if (!p)
return -EINVAL;
if (!p) {
xsprintf(buf, "0x%x", i);
p = buf;
}
add = strlen(p);
@ -91,11 +93,10 @@ int capability_set_to_string_alloc(uint64_t set, char **s) {
int capability_set_from_string(const char *s, uint64_t *set) {
uint64_t val = 0;
const char *p;
assert(set);
for (p = s;;) {
for (const char *p = s;;) {
_cleanup_free_ char *word = NULL;
int r;

31
src/basic/capability-util.c
View File

@ -31,8 +31,8 @@ int have_effective_cap(int value) {
return fv == CAP_SET;
}
unsigned long cap_last_cap(void) {
static thread_local unsigned long saved;
unsigned cap_last_cap(void) {
static thread_local unsigned saved;
static thread_local bool valid = false;
_cleanup_free_ char *content = NULL;
unsigned long p = 0;
@ -65,7 +65,7 @@ unsigned long cap_last_cap(void) {
if (prctl(PR_CAPBSET_READ, p) < 0) {
/* Hmm, look downwards, until we find one that works */
for (p--; p > 0; p --)
for (p--; p > 0; p--)
if (prctl(PR_CAPBSET_READ, p) >= 0)
break;
@ -84,12 +84,10 @@ unsigned long cap_last_cap(void) {
}
int capability_update_inherited_set(cap_t caps, uint64_t set) {
unsigned long i;
/* Add capabilities in the set to the inherited caps, drops capabilities not in the set.
* Do not apply them yet. */
for (i = 0; i <= cap_last_cap(); i++) {
for (unsigned i = 0; i <= cap_last_cap(); i++) {
cap_flag_value_t flag = set & (UINT64_C(1) << i) ? CAP_SET : CAP_CLEAR;
cap_value_t v;
@ -104,11 +102,10 @@ int capability_update_inherited_set(cap_t caps, uint64_t set) {
int capability_ambient_set_apply(uint64_t set, bool also_inherit) {
_cleanup_cap_free_ cap_t caps = NULL;
unsigned long i;
int r;
/* Remove capabilities requested in ambient set, but not in the bounding set */
for (i = 0; i <= cap_last_cap(); i++) {
for (unsigned i = 0; i <= cap_last_cap(); i++) {
if (set == 0)
break;
@ -140,7 +137,7 @@ int capability_ambient_set_apply(uint64_t set, bool also_inherit) {
return -errno;
}
for (i = 0; i <= cap_last_cap(); i++) {
for (unsigned i = 0; i <= cap_last_cap(); i++) {
if (set & (UINT64_C(1) << i)) {
@ -167,7 +164,6 @@ int capability_ambient_set_apply(uint64_t set, bool also_inherit) {
int capability_bounding_set_drop(uint64_t keep, bool right_now) {
_cleanup_cap_free_ cap_t before_cap = NULL, after_cap = NULL;
cap_flag_value_t fv;
unsigned long i;
int r;
/* If we are run as PID 1 we will lack CAP_SETPCAP by default
@ -204,7 +200,7 @@ int capability_bounding_set_drop(uint64_t keep, bool right_now) {
if (!after_cap)
return -errno;
for (i = 0; i <= cap_last_cap(); i++) {
for (unsigned i = 0; i <= cap_last_cap(); i++) {
cap_value_t v;
if ((keep & (UINT64_C(1) << i)))
@ -390,7 +386,6 @@ bool ambient_capabilities_supported(void) {
}
bool capability_quintet_mangle(CapabilityQuintet *q) {
unsigned long i;
uint64_t combined, drop = 0;
bool ambient_supported;
@ -402,7 +397,7 @@ bool capability_quintet_mangle(CapabilityQuintet *q) {
if (ambient_supported)
combined |= q->ambient;
for (i = 0; i <= cap_last_cap(); i++) {
for (unsigned i = 0; i <= cap_last_cap(); i++) {
unsigned long bit = UINT64_C(1) << i;
if (!FLAGS_SET(combined, bit))
continue;
@ -431,16 +426,15 @@ int capability_quintet_enforce(const CapabilityQuintet *q) {
int r;
if (q->ambient != (uint64_t) -1) {
unsigned long i;
bool changed = false;
c = cap_get_proc();
if (!c)
return -errno;
/* In order to raise the ambient caps set we first need to raise the matching inheritable + permitted
* cap */
for (i = 0; i <= cap_last_cap(); i++) {
/* In order to raise the ambient caps set we first need to raise the matching
* inheritable + permitted cap */
for (unsigned i = 0; i <= cap_last_cap(); i++) {
uint64_t m = UINT64_C(1) << i;
cap_value_t cv = (cap_value_t) i;
cap_flag_value_t old_value_inheritable, old_value_permitted;
@ -475,7 +469,6 @@ int capability_quintet_enforce(const CapabilityQuintet *q) {
if (q->inheritable != (uint64_t) -1 || q->permitted != (uint64_t) -1 || q->effective != (uint64_t) -1) {
bool changed = false;
unsigned long i;
if (!c) {
c = cap_get_proc();
@ -483,7 +476,7 @@ int capability_quintet_enforce(const CapabilityQuintet *q) {
return -errno;
}
for (i = 0; i <= cap_last_cap(); i++) {
for (unsigned i = 0; i <= cap_last_cap(); i++) {
uint64_t m = UINT64_C(1) << i;
cap_value_t cv = (cap_value_t) i;

2
src/basic/capability-util.h
View File

@ -12,7 +12,7 @@
#define CAP_ALL (uint64_t) -1
unsigned long cap_last_cap(void);
unsigned cap_last_cap(void);
int have_effective_cap(int value);
int capability_bounding_set_drop(uint64_t keep, bool right_now);
int capability_bounding_set_drop_usermode(uint64_t keep);

5
src/libsystemd/sd-bus/bus-creds.c
View File

@ -650,16 +650,15 @@ _public_ int sd_bus_creds_get_description(sd_bus_creds *c, const char **ret) {
}
static int has_cap(sd_bus_creds *c, size_t offset, int capability) {
unsigned long lc;
size_t sz;
assert(c);
assert(capability >= 0);
assert(c->capability);
lc = cap_last_cap();
unsigned lc = cap_last_cap();
if ((unsigned long) capability > lc)
if ((unsigned) capability > lc)
return 0;
/* If the last cap is 63, then there are 64 caps defined, and we need 2 entries á 32bit hence. *

10
src/test/test-cap-list.c
View File

@ -12,12 +12,10 @@
/* verify the capability parser */
static void test_cap_list(void) {
int i;
assert_se(!capability_to_name(-1));
assert_se(!capability_to_name(capability_list_length()));
for (i = 0; i < capability_list_length(); i++) {
for (int i = 0; i < capability_list_length(); i++) {
const char *n;
assert_se(n = capability_to_name(i));
@ -31,9 +29,11 @@ static void test_cap_list(void) {
assert_se(capability_from_name("cAp_aUdIt_rEAd") == CAP_AUDIT_READ);
assert_se(capability_from_name("0") == 0);
assert_se(capability_from_name("15") == 15);
assert_se(capability_from_name("63") == 63);
assert_se(capability_from_name("64") == -EINVAL);
assert_se(capability_from_name("-1") == -EINVAL);
for (i = 0; i < capability_list_length(); i++) {
for (int i = 0; i < capability_list_length(); i++) {
_cleanup_cap_free_charp_ char *a = NULL;
const char *b;
unsigned u;
@ -65,7 +65,7 @@ static void test_capability_set_one(uint64_t c, const char *t) {
free(t1);
assert_se(t1 = strjoin("'cap_chown cap_dac_override' \"cap_setgid cap_setuid\"", t,
" hogehoge foobar 12345 3.14 -3 ", t));
" hogehoge foobar 18446744073709551616 3.14 -3 ", t));
assert_se(capability_set_from_string(t1, &c1) == 0);
assert_se(c1 == c_masked);
}

2
src/test/test-capability.c
View File

@ -243,7 +243,7 @@ static void test_ensure_cap_64bit(void) {
assert_se(p <= 63);
/* Also check for the header definition */
assert_se(CAP_LAST_CAP <= 63);
assert_cc(CAP_LAST_CAP <= 63);
}
int main(int argc, char *argv[]) {