diff options
-rw-r--r-- | src/core/execute.c | 41 | ||||
-rw-r--r-- | src/core/load-fragment.c | 54 | ||||
-rw-r--r-- | src/shared/seccomp-util.c | 128 | ||||
-rw-r--r-- | src/shared/seccomp-util.h | 32 |
4 files changed, 155 insertions, 100 deletions
diff --git a/src/core/execute.c b/src/core/execute.c index e63a12f934..18bb67cda9 100644 --- a/src/core/execute.c +++ b/src/core/execute.c @@ -1578,10 +1578,7 @@ finish: } static int apply_private_devices(Unit *u, const ExecContext *c) { - const SystemCallFilterSet *set; scmp_filter_ctx *seccomp; - const char *sys; - bool syscalls_found = false; int r; assert(c); @@ -1599,43 +1596,9 @@ static int apply_private_devices(Unit *u, const ExecContext *c) { if (r < 0) goto finish; - for (set = syscall_filter_sets; set->set_name; set++) - if (streq(set->set_name, "@raw-io")) { - syscalls_found = true; - break; - } - - /* We should never fail here */ - if (!syscalls_found) { - r = -EOPNOTSUPP; + r = seccomp_add_syscall_filter_set(seccomp, syscall_filter_sets + SYSCALL_FILTER_SET_RAW_IO, SCMP_ACT_ERRNO(EPERM)); + if (r < 0) goto finish; - } - - NULSTR_FOREACH(sys, set->value) { - int id; - bool add = true; - -#ifndef __NR_s390_pci_mmio_read - if (streq(sys, "s390_pci_mmio_read")) - add = false; -#endif -#ifndef __NR_s390_pci_mmio_write - if (streq(sys, "s390_pci_mmio_write")) - add = false; -#endif - - if (!add) - continue; - - id = seccomp_syscall_resolve_name(sys); - - r = seccomp_rule_add( - seccomp, - SCMP_ACT_ERRNO(EPERM), - id, 0); - if (r < 0) - goto finish; - } r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0); if (r < 0) diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index 6f68e23340..118b39c1cf 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -2618,6 +2618,7 @@ int config_parse_documentation(const char *unit, } #ifdef HAVE_SECCOMP + static int syscall_filter_parse_one( const char *unit, const char *filename, @@ -2628,27 +2629,29 @@ static int syscall_filter_parse_one( bool warn) { int r; - if (*t == '@') { - const SystemCallFilterSet *set; + if (t[0] == '@') { + const SyscallFilterSet *set; + const char *i; - for (set = syscall_filter_sets; set->set_name; set++) - if (streq(set->set_name, t)) { - const char *sys; + set = syscall_filter_set_find(t); + if (!set) { + if (warn) + log_syntax(unit, LOG_WARNING, filename, line, 0, "Don't know system call group, ignoring: %s", t); + return 0; + } - NULSTR_FOREACH(sys, set->value) { - r = syscall_filter_parse_one(unit, filename, line, c, invert, sys, false); - if (r < 0) - return r; - } - break; - } + NULSTR_FOREACH(i, set->value) { + r = syscall_filter_parse_one(unit, filename, line, c, invert, i, false); + if (r < 0) + return r; + } } else { int id; id = seccomp_syscall_resolve_name(t); if (id == __NR_SCMP_ERROR) { if (warn) - log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse system call, ignoring: %s", t); + log_syntax(unit, LOG_WARNING, filename, line, 0, "Failed to parse system call, ignoring: %s", t); return 0; } @@ -2662,8 +2665,9 @@ static int syscall_filter_parse_one( if (r < 0) return log_oom(); } else - set_remove(c->syscall_filter, INT_TO_PTR(id + 1)); + (void) set_remove(c->syscall_filter, INT_TO_PTR(id + 1)); } + return 0; } @@ -2682,8 +2686,7 @@ int config_parse_syscall_filter( ExecContext *c = data; Unit *u = userdata; bool invert = false; - const char *word, *state; - size_t l; + const char *p; int r; assert(filename); @@ -2722,19 +2725,24 @@ int config_parse_syscall_filter( } } - FOREACH_WORD_QUOTED(word, l, rvalue, state) { - _cleanup_free_ char *t = NULL; + p = rvalue; + for (;;) { + _cleanup_free_ char *word = NULL; - t = strndup(word, l); - if (!t) + r = extract_first_word(&p, &word, NULL, 0); + if (r == 0) + break; + if (r == -ENOMEM) return log_oom(); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid syntax, ignoring: %s", rvalue); + break; + } - r = syscall_filter_parse_one(unit, filename, line, c, invert, t, true); + r = syscall_filter_parse_one(unit, filename, line, c, invert, word, true); if (r < 0) return r; } - if (!isempty(state)) - log_syntax(unit, LOG_ERR, filename, line, 0, "Trailing garbage, ignoring."); /* Turn on NNP, but only if it wasn't configured explicitly * before, and only if we are in user mode. */ diff --git a/src/shared/seccomp-util.c b/src/shared/seccomp-util.c index 8116c7671f..1d51f3fd1f 100644 --- a/src/shared/seccomp-util.c +++ b/src/shared/seccomp-util.c @@ -26,6 +26,7 @@ #include "macro.h" #include "seccomp-util.h" #include "string-util.h" +#include "util.h" const char* seccomp_arch_to_string(uint32_t c) { @@ -132,28 +133,30 @@ bool is_seccomp_available(void) { return cached_enabled; } -const SystemCallFilterSet syscall_filter_sets[] = { - { +const SyscallFilterSet syscall_filter_sets[_SYSCALL_FILTER_SET_MAX] = { + [SYSCALL_FILTER_SET_CLOCK] = { /* Clock */ - .set_name = "@clock", + .name = "@clock", .value = "adjtimex\0" "clock_adjtime\0" "clock_settime\0" "settimeofday\0" "stime\0" - }, { + }, + [SYSCALL_FILTER_SET_CPU_EMULATION] = { /* CPU emulation calls */ - .set_name = "@cpu-emulation", + .name = "@cpu-emulation", .value = "modify_ldt\0" "subpage_prot\0" "switch_endian\0" "vm86\0" "vm86old\0" - }, { + }, + [SYSCALL_FILTER_SET_DEBUG] = { /* Debugging/Performance Monitoring/Tracing */ - .set_name = "@debug", + .name = "@debug", .value = "lookup_dcookie\0" "perf_event_open\0" @@ -161,11 +164,14 @@ const SystemCallFilterSet syscall_filter_sets[] = { "process_vm_writev\0" "ptrace\0" "rtas\0" +#ifdef __NR_s390_runtime_instr "s390_runtime_instr\0" +#endif "sys_debug_setcontext\0" - }, { + }, + [SYSCALL_FILTER_SET_DEFAULT] = { /* Default list */ - .set_name = "@default", + .name = "@default", .value = "execve\0" "exit\0" @@ -173,9 +179,10 @@ const SystemCallFilterSet syscall_filter_sets[] = { "getrlimit\0" /* make sure processes can query stack size and such */ "rt_sigreturn\0" "sigreturn\0" - }, { + }, + [SYSCALL_FILTER_SET_IO_EVENT] = { /* Event loop use */ - .set_name = "@io-event", + .name = "@io-event", .value = "_newselect\0" "epoll_create1\0" @@ -191,9 +198,10 @@ const SystemCallFilterSet syscall_filter_sets[] = { "ppoll\0" "pselect6\0" "select\0" - }, { + }, + [SYSCALL_FILTER_SET_IPC] = { /* Message queues, SYSV IPC or other IPC: unusual */ - .set_name = "@ipc", + .name = "@ipc", .value = "ipc\0" "mq_getsetattr\0" "mq_notify\0" @@ -215,23 +223,26 @@ const SystemCallFilterSet syscall_filter_sets[] = { "shmctl\0" "shmdt\0" "shmget\0" - }, { + }, + [SYSCALL_FILTER_SET_KEYRING] = { /* Keyring */ - .set_name = "@keyring", + .name = "@keyring", .value = "add_key\0" "keyctl\0" "request_key\0" - }, { + }, + [SYSCALL_FILTER_SET_MODULE] = { /* Kernel module control */ - .set_name = "@module", + .name = "@module", .value = "delete_module\0" "finit_module\0" "init_module\0" - }, { + }, + [SYSCALL_FILTER_SET_MOUNT] = { /* Mounting */ - .set_name = "@mount", + .name = "@mount", .value = "chroot\0" "mount\0" @@ -239,9 +250,10 @@ const SystemCallFilterSet syscall_filter_sets[] = { "pivot_root\0" "umount2\0" "umount\0" - }, { + }, + [SYSCALL_FILTER_SET_NETWORK_IO] = { /* Network or Unix socket IO, should not be needed if not network facing */ - .set_name = "@network-io", + .name = "@network-io", .value = "accept4\0" "accept\0" @@ -264,9 +276,10 @@ const SystemCallFilterSet syscall_filter_sets[] = { "socket\0" "socketcall\0" "socketpair\0" - }, { + }, + [SYSCALL_FILTER_SET_OBSOLETE] = { /* Unusual, obsolete or unimplemented, some unknown even to libseccomp */ - .set_name = "@obsolete", + .name = "@obsolete", .value = "_sysctl\0" "afs_syscall\0" @@ -292,9 +305,10 @@ const SystemCallFilterSet syscall_filter_sets[] = { "uselib\0" "ustat\0" "vserver\0" - }, { + }, + [SYSCALL_FILTER_SET_PRIVILEGED] = { /* Nice grab-bag of all system calls which need superuser capabilities */ - .set_name = "@privileged", + .name = "@privileged", .value = "@clock\0" "@module\0" @@ -333,9 +347,10 @@ const SystemCallFilterSet syscall_filter_sets[] = { "swapon\0" "sysctl\0" "vhangup\0" - }, { + }, + [SYSCALL_FILTER_SET_PROCESS] = { /* Process control, execution, namespaces */ - .set_name = "@process", + .name = "@process", .value = "arch_prctl\0" "clone\0" @@ -349,19 +364,66 @@ const SystemCallFilterSet syscall_filter_sets[] = { "tkill\0" "unshare\0" "vfork\0" - }, { + }, + [SYSCALL_FILTER_SET_RAW_IO] = { /* Raw I/O ports */ - .set_name = "@raw-io", + .name = "@raw-io", .value = "ioperm\0" "iopl\0" "pciconfig_iobase\0" "pciconfig_read\0" "pciconfig_write\0" +#ifdef __NR_s390_pci_mmio_read "s390_pci_mmio_read\0" +#endif +#ifdef __NR_s390_pci_mmio_write "s390_pci_mmio_write\0" - }, { - .set_name = NULL, - .value = NULL - } +#endif + }, }; + +const SyscallFilterSet *syscall_filter_set_find(const char *name) { + unsigned i; + + if (isempty(name) || name[0] != '@') + return NULL; + + for (i = 0; i < _SYSCALL_FILTER_SET_MAX; i++) + if (streq(syscall_filter_sets[i].name, name)) + return syscall_filter_sets + i; + + return NULL; +} + +int seccomp_add_syscall_filter_set(scmp_filter_ctx seccomp, const SyscallFilterSet *set, uint32_t action) { + const char *sys; + int r; + + assert(seccomp); + assert(set); + + NULSTR_FOREACH(sys, set->value) { + int id; + + if (sys[0] == '@') { + const SyscallFilterSet *other; + + other = syscall_filter_set_find(sys); + if (!other) + return -EINVAL; + + r = seccomp_add_syscall_filter_set(seccomp, other, action); + } else { + id = seccomp_syscall_resolve_name(sys); + if (id == __NR_SCMP_ERROR) + return -EINVAL; + + r = seccomp_rule_add(seccomp, action, id, 0); + } + if (r < 0) + return r; + } + + return 0; +} diff --git a/src/shared/seccomp-util.h b/src/shared/seccomp-util.h index cca7c17912..34fd49c122 100644 --- a/src/shared/seccomp-util.h +++ b/src/shared/seccomp-util.h @@ -29,9 +29,31 @@ int seccomp_add_secondary_archs(scmp_filter_ctx *c); bool is_seccomp_available(void); -typedef struct SystemCallFilterSet { - const char *set_name; +typedef struct SyscallFilterSet { + const char *name; const char *value; -} SystemCallFilterSet; - -extern const SystemCallFilterSet syscall_filter_sets[]; +} SyscallFilterSet; + +enum { + SYSCALL_FILTER_SET_CLOCK, + SYSCALL_FILTER_SET_CPU_EMULATION, + SYSCALL_FILTER_SET_DEBUG, + SYSCALL_FILTER_SET_DEFAULT, + SYSCALL_FILTER_SET_IO_EVENT, + SYSCALL_FILTER_SET_IPC, + SYSCALL_FILTER_SET_KEYRING, + SYSCALL_FILTER_SET_MODULE, + SYSCALL_FILTER_SET_MOUNT, + SYSCALL_FILTER_SET_NETWORK_IO, + SYSCALL_FILTER_SET_OBSOLETE, + SYSCALL_FILTER_SET_PRIVILEGED, + SYSCALL_FILTER_SET_PROCESS, + SYSCALL_FILTER_SET_RAW_IO, + _SYSCALL_FILTER_SET_MAX +}; + +extern const SyscallFilterSet syscall_filter_sets[]; + +const SyscallFilterSet *syscall_filter_set_find(const char *name); + +int seccomp_add_syscall_filter_set(scmp_filter_ctx seccomp, const SyscallFilterSet *set, uint32_t action); |