diff options
Diffstat (limited to 'src/core/load-fragment.c')
| -rw-r--r-- | src/core/load-fragment.c | 96 |
1 files changed, 62 insertions, 34 deletions
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index 7a2d32ddbd..06ff18b573 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -33,6 +33,11 @@ #include <sys/stat.h> #include <sys/time.h> #include <sys/resource.h> +#ifdef HAVE_SECCOMP +#include <seccomp.h> + +#include "set.h" +#endif #include "sd-messages.h" #include "unit.h" @@ -47,13 +52,12 @@ #include "unit-printf.h" #include "utf8.h" #include "path-util.h" -#include "syscall-list.h" #include "env-util.h" #include "cgroup.h" #include "bus-util.h" #include "bus-error.h" -#ifndef HAVE_SYSV_COMPAT +#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP) int config_parse_warn_compat(const char *unit, const char *filename, unsigned line, @@ -1916,16 +1920,7 @@ int config_parse_documentation(const char *unit, return r; } -static void syscall_set(uint32_t *p, int nr) { - nr = SYSCALL_TO_INDEX(nr); - p[nr >> 4] |= 1 << (nr & 31); -} - -static void syscall_unset(uint32_t *p, int nr) { - nr = SYSCALL_TO_INDEX(nr); - p[nr >> 4] &= ~(1 << (nr & 31)); -} - +#ifdef HAVE_SECCOMP int config_parse_syscall_filter(const char *unit, const char *filename, unsigned line, @@ -1936,13 +1931,23 @@ int config_parse_syscall_filter(const char *unit, const char *rvalue, void *data, void *userdata) { - ExecContext *c = data; Unit *u = userdata; bool invert = false; char *w; size_t l; char *state; + _cleanup_strv_free_ char **syscalls = strv_new(NULL, NULL); + _cleanup_free_ char *sorted_syscalls = NULL; + uint32_t action = SCMP_ACT_ALLOW; + Iterator i; + void *e; + static char const *default_syscalls[] = {"execve", + "exit", + "exit_group", + "rt_sigreturn", + "sigreturn", + NULL}; assert(filename); assert(lvalue); @@ -1951,34 +1956,37 @@ int config_parse_syscall_filter(const char *unit, if (isempty(rvalue)) { /* Empty assignment resets the list */ - free(c->syscall_filter); - c->syscall_filter = NULL; + set_free(c->filtered_syscalls); + c->filtered_syscalls= NULL; + free(c->syscall_filter_string); + c->syscall_filter_string = NULL; return 0; } if (rvalue[0] == '~') { invert = true; + action = SCMP_ACT_KILL; rvalue++; } - if (!c->syscall_filter) { - size_t n; + if (!c->filtered_syscalls) { + c->filtered_syscalls = set_new(trivial_hash_func, trivial_compare_func); + if (invert) + c->syscall_filter_default_action = SCMP_ACT_ALLOW; + else { + char const **syscall; - n = (syscall_max() + 31) >> 4; - c->syscall_filter = new(uint32_t, n); - if (!c->syscall_filter) - return log_oom(); + c->syscall_filter_default_action = SCMP_ACT_KILL; - memset(c->syscall_filter, invert ? 0xFF : 0, n * sizeof(uint32_t)); + /* accept default syscalls if we are on a whitelist */ + STRV_FOREACH(syscall, default_syscalls) { + int id = seccomp_syscall_resolve_name(*syscall); + if (id < 0) + continue; - /* Add these by default */ - syscall_set(c->syscall_filter, __NR_execve); - syscall_set(c->syscall_filter, __NR_rt_sigreturn); -#ifdef __NR_sigreturn - syscall_set(c->syscall_filter, __NR_sigreturn); -#endif - syscall_set(c->syscall_filter, __NR_exit_group); - syscall_set(c->syscall_filter, __NR_exit); + set_replace(c->filtered_syscalls, INT_TO_PTR(id + 1)); + } + } } FOREACH_WORD_QUOTED(w, l, rvalue, state) { @@ -1989,23 +1997,39 @@ int config_parse_syscall_filter(const char *unit, if (!t) return log_oom(); - id = syscall_from_name(t); + id = seccomp_syscall_resolve_name(t); if (id < 0) { log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Failed to parse syscall, ignoring: %s", t); continue; } - if (invert) - syscall_unset(c->syscall_filter, id); + /* If we previously wanted to forbid a syscall + * and now we want to allow it, then remove it from the list + * libseccomp will also return -EPERM if we try to add + * a rule with the same action as the default + */ + if (action == c->syscall_filter_default_action) + set_remove(c->filtered_syscalls, INT_TO_PTR(id + 1)); else - syscall_set(c->syscall_filter, id); + set_replace(c->filtered_syscalls, INT_TO_PTR(id + 1)); + } + + SET_FOREACH(e, c->filtered_syscalls, i) { + char *name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(e) - 1); + strv_push(&syscalls, name); } + sorted_syscalls = strv_join(strv_sort(syscalls), " "); + if (invert) + c->syscall_filter_string = strv_join(STRV_MAKE("~", sorted_syscalls, NULL), ""); + else + c->syscall_filter_string = strdup(sorted_syscalls); c->no_new_privileges = true; return 0; } +#endif int config_parse_unit_slice( const char *unit, @@ -2778,7 +2802,11 @@ void unit_dump_config_items(FILE *f) { { config_parse_set_status, "STATUS" }, { config_parse_service_sockets, "SOCKETS" }, { config_parse_environ, "ENVIRON" }, +#ifdef HAVE_SECCOMP { config_parse_syscall_filter, "SYSCALL" }, +#else + { config_parse_warn_compat, "NOTSUPPORTED" }, +#endif { config_parse_cpu_shares, "SHARES" }, { config_parse_memory_limit, "LIMIT" }, { config_parse_device_allow, "DEVICE" }, |