diff options
Diffstat (limited to 'src/shared/seccomp-util.c')
| -rw-r--r-- | src/shared/seccomp-util.c | 185 |
1 files changed, 148 insertions, 37 deletions
diff --git a/src/shared/seccomp-util.c b/src/shared/seccomp-util.c index 8116c7671f..6252cd16a6 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) { @@ -73,7 +74,34 @@ int seccomp_arch_from_string(const char *n, uint32_t *ret) { return 0; } -int seccomp_add_secondary_archs(scmp_filter_ctx *c) { +int seccomp_init_conservative(scmp_filter_ctx *ret, uint32_t default_action) { + scmp_filter_ctx seccomp; + int r; + + /* Much like seccomp_init(), but tries to be a bit more conservative in its defaults: all secondary archs are + * added by default, and NNP is turned off. */ + + seccomp = seccomp_init(default_action); + if (!seccomp) + return -ENOMEM; + + r = seccomp_add_secondary_archs(seccomp); + if (r < 0) + goto finish; + + r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0); + if (r < 0) + goto finish; + + *ret = seccomp; + return 0; + +finish: + seccomp_release(seccomp); + return r; +} + +int seccomp_add_secondary_archs(scmp_filter_ctx c) { #if defined(__i386__) || defined(__x86_64__) int r; @@ -110,7 +138,6 @@ int seccomp_add_secondary_archs(scmp_filter_ctx *c) { #endif return 0; - } static bool is_basic_seccomp_available(void) { @@ -132,28 +159,30 @@ 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 +190,14 @@ 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 +205,10 @@ 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 +224,10 @@ 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" @@ -215,33 +249,36 @@ 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" - "oldumount\0" "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 +301,10 @@ 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 +330,10 @@ 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" @@ -331,11 +370,12 @@ const SystemCallFilterSet syscall_filter_sets[] = { "setuid\0" "swapoff\0" "swapon\0" - "sysctl\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 +389,90 @@ 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; +} + +int seccomp_load_filter_set(uint32_t default_action, const SyscallFilterSet *set, uint32_t action) { + scmp_filter_ctx seccomp; + int r; + + assert(set); + + /* The one-stop solution: allocate a seccomp object, add a filter to it, and apply it */ + + r = seccomp_init_conservative(&seccomp, default_action); + if (r < 0) + return r; + + r = seccomp_add_syscall_filter_set(seccomp, set, action); + if (r < 0) + goto finish; + + r = seccomp_load(seccomp); + +finish: + seccomp_release(seccomp); + return r; + +} |