From 240c55f1526300daac640ef2c1f4941de4579493 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Thu, 9 Jul 2020 23:15:47 +0200

Subject: [PATCH] basic/cap-list: parse/print numerical capabilities

We would refuse to print capabilities which were didn't have a name

for. The kernel adds new capabilities from time to time, most recently

cap_bpf. 'systmectl show -p CapabilityBoundingSet ...' would fail with

"Failed to parse bus message: Invalid argument" because

capability_set_to_string_alloc() would fail with -EINVAL. So let's

print such capabilities in hexadecimal:

CapabilityBoundingSet=cap_chown cap_dac_override cap_dac_read_search

  cap_fowner cap_fsetid cap_kill cap_setgid cap_setuid cap_setpcap

  cap_linux_immutable cap_net_bind_service cap_net_broadcast cap_net_admin

  cap_net_raw cap_ipc_lock cap_ipc_owner 0x10 0x11 0x12 0x13 0x14 0x15 0x16

  0x17 0x18 0x19 0x1a ...

For symmetry, also allow capabilities that we don't know to be specified.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1853736.

(cherry picked from commit 417770f3033c426ca848b158d0bf057cd8ad1329)

Resolves: #1946943

---

 src/basic/cap-list.c     | 10 +++++++---

 src/test/test-cap-list.c |  4 +++-

 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/basic/cap-list.c b/src/basic/cap-list.c

index bfcda33520..56a81c7dfc 100644

--- a/src/basic/cap-list.c

+++ b/src/basic/cap-list.c

@@ -10,6 +10,7 @@

 #include "macro.h"

 #include "missing.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);

@@ -37,7 +38,7 @@ int capability_from_name(const char *name) {

         /* Try to parse numeric capability */

         r = safe_atoi(name, &i);

         if (r >= 0) {

-                if (i >= 0 && i < (int) ELEMENTSOF(capability_names))

+                if (i >= 0 && i < 64)

                         return i;

                 else

                         return -EINVAL;

@@ -65,11 +66,14 @@ int capability_set_to_string_alloc(uint64_t set, char **s) {

         for (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%lx", i);

+                                p = buf;

+                        }

                         add = strlen(p);

diff --git a/src/test/test-cap-list.c b/src/test/test-cap-list.c

index de5fa729cc..84bbb7b7e7 100644

--- a/src/test/test-cap-list.c

+++ b/src/test/test-cap-list.c

@@ -30,6 +30,8 @@ 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++) {

@@ -64,7 +66,7 @@ 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);

 }