diff options
| -rw-r--r-- | man/systemd.exec.xml | 9 | ||||
| -rw-r--r-- | src/basic/raw-clone.h | 4 | ||||
| -rw-r--r-- | src/shared/seccomp-util.c | 45 | ||||
| -rw-r--r-- | src/shared/seccomp-util.h | 7 | ||||
| -rw-r--r-- | src/test/test-seccomp.c | 3 |
5 files changed, 55 insertions, 13 deletions
diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index fd47b0a20a..e7e5d6b0c7 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -1554,11 +1554,10 @@ <citerefentry><refentrytitle>setns</refentrytitle><manvolnum>2</manvolnum></citerefentry> system calls, taking the specified flags parameters into account. Note that — if this option is used — in addition to restricting creation and switching of the specified types of namespaces (or all of them, if true) access to the - <function>setns()</function> system call with a zero flags parameter is prohibited. - If running in user mode, or in system mode, but without the <constant>CAP_SYS_ADMIN</constant> - capability (e.g. setting <varname>User=</varname>), <varname>NoNewPrivileges=yes</varname> - is implied. - </para></listitem> + <function>setns()</function> system call with a zero flags parameter is prohibited. This setting is only + supported on x86, x86-64, s390 and s390x, and enforces no restrictions on other architectures. If running in user + mode, or in system mode, but without the <constant>CAP_SYS_ADMIN</constant> capability (e.g. setting + <varname>User=</varname>), <varname>NoNewPrivileges=yes</varname> is implied. </para></listitem> </varlistentry> <varlistentry> diff --git a/src/basic/raw-clone.h b/src/basic/raw-clone.h index d473828999..c6e531ada4 100644 --- a/src/basic/raw-clone.h +++ b/src/basic/raw-clone.h @@ -47,8 +47,8 @@ static inline int raw_clone(unsigned long flags) { assert((flags & (CLONE_VM|CLONE_PARENT_SETTID|CLONE_CHILD_SETTID| CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0); -#if defined(__s390__) || defined(__CRIS__) - /* On s390 and cris the order of the first and second arguments +#if defined(__s390x__) || defined(__s390__) || defined(__CRIS__) + /* On s390/s390x and cris the order of the first and second arguments * of the raw clone() system call is reversed. */ return (int) syscall(__NR_clone, NULL, flags); #elif defined(__sparc__) && defined(__arch64__) diff --git a/src/shared/seccomp-util.c b/src/shared/seccomp-util.c index 44706669b4..e35f18471c 100644 --- a/src/shared/seccomp-util.c +++ b/src/shared/seccomp-util.c @@ -750,10 +750,35 @@ int seccomp_restrict_namespaces(unsigned long retain) { SECCOMP_FOREACH_LOCAL_ARCH(arch) { _cleanup_(seccomp_releasep) scmp_filter_ctx seccomp = NULL; + int clone_reversed_order = -1; unsigned i; log_debug("Operating on architecture: %s", seccomp_arch_to_string(arch)); + switch (arch) { + + case SCMP_ARCH_X86_64: + case SCMP_ARCH_X86: + case SCMP_ARCH_X32: + clone_reversed_order = 0; + break; + + case SCMP_ARCH_S390: + case SCMP_ARCH_S390X: + /* On s390/s390x the first two parameters to clone are switched */ + clone_reversed_order = 1; + break; + + /* Please add more definitions here, if you port systemd to other architectures! */ + +#if !defined(__i386__) && !defined(__x86_64__) && !defined(__s390__) && !defined(__s390x__) +#warning "Consider adding the right clone() syscall definitions here!" +#endif + } + + if (clone_reversed_order < 0) /* we don't know the right order, let's ignore this arch... */ + continue; + r = seccomp_init_for_arch(&seccomp, arch, SCMP_ACT_ALLOW); if (r < 0) return r; @@ -802,12 +827,20 @@ int seccomp_restrict_namespaces(unsigned long retain) { break; } - r = seccomp_rule_add_exact( - seccomp, - SCMP_ACT_ERRNO(EPERM), - SCMP_SYS(clone), - 1, - SCMP_A0(SCMP_CMP_MASKED_EQ, f, f)); + if (clone_reversed_order == 0) + r = seccomp_rule_add_exact( + seccomp, + SCMP_ACT_ERRNO(EPERM), + SCMP_SYS(clone), + 1, + SCMP_A0(SCMP_CMP_MASKED_EQ, f, f)); + else + r = seccomp_rule_add_exact( + seccomp, + SCMP_ACT_ERRNO(EPERM), + SCMP_SYS(clone), + 1, + SCMP_A1(SCMP_CMP_MASKED_EQ, f, f)); if (r < 0) { log_debug_errno(r, "Failed to add clone() rule for architecture %s, skipping: %m", seccomp_arch_to_string(arch)); break; diff --git a/src/shared/seccomp-util.h b/src/shared/seccomp-util.h index bfbfb5ab3d..61f94de638 100644 --- a/src/shared/seccomp-util.h +++ b/src/shared/seccomp-util.h @@ -91,6 +91,13 @@ int seccomp_memory_deny_write_execute(void); #define SECCOMP_MEMORY_DENY_WRITE_EXECUTE_BROKEN 1 #endif +/* we don't know the right order of the clone() parameters except for these archs, for now */ +#if defined(__x86_64__) || defined(__i386__) || defined(__s390x__) || defined(__s390__) +#define SECCOMP_RESTRICT_NAMESPACES_BROKEN 0 +#else +#define SECCOMP_RESTRICT_NAMESPACES_BROKEN 1 +#endif + extern const uint32_t seccomp_local_archs[]; #define SECCOMP_FOREACH_LOCAL_ARCH(arch) \ diff --git a/src/test/test-seccomp.c b/src/test/test-seccomp.c index 3659238810..34a1275162 100644 --- a/src/test/test-seccomp.c +++ b/src/test/test-seccomp.c @@ -158,6 +158,8 @@ static void test_restrict_namespace(void) { assert_se(streq(s, "cgroup ipc net mnt pid user uts")); assert_se(namespace_flag_from_string_many(s, &ul) == 0 && ul == NAMESPACE_FLAGS_ALL); +#if SECCOMP_RESTRICT_NAMESPACES_BROKEN == 0 + if (!is_seccomp_available()) return; if (geteuid() != 0) @@ -216,6 +218,7 @@ static void test_restrict_namespace(void) { } assert_se(wait_for_terminate_and_warn("nsseccomp", pid, true) == EXIT_SUCCESS); +#endif } static void test_protect_sysctl(void) { |