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-rw-r--r--src/shared/seccomp-util.c369
1 files changed, 312 insertions, 57 deletions
diff --git a/src/shared/seccomp-util.c b/src/shared/seccomp-util.c
index 8656d112b8..c9b24f1065 100644
--- a/src/shared/seccomp-util.c
+++ b/src/shared/seccomp-util.c
@@ -20,25 +20,58 @@
#include <errno.h>
#include <seccomp.h>
#include <stddef.h>
+#include <sys/prctl.h>
+#include <linux/seccomp.h>
#include "macro.h"
#include "seccomp-util.h"
#include "string-util.h"
+#include "util.h"
const char* seccomp_arch_to_string(uint32_t c) {
+ /* Maintain order used in <seccomp.h>.
+ *
+ * Names used here should be the same as those used for ConditionArchitecture=,
+ * except for "subarchitectures" like x32. */
- if (c == SCMP_ARCH_NATIVE)
+ switch(c) {
+ case SCMP_ARCH_NATIVE:
return "native";
- if (c == SCMP_ARCH_X86)
+ case SCMP_ARCH_X86:
return "x86";
- if (c == SCMP_ARCH_X86_64)
+ case SCMP_ARCH_X86_64:
return "x86-64";
- if (c == SCMP_ARCH_X32)
+ case SCMP_ARCH_X32:
return "x32";
- if (c == SCMP_ARCH_ARM)
+ case SCMP_ARCH_ARM:
return "arm";
-
- return NULL;
+ case SCMP_ARCH_AARCH64:
+ return "arm64";
+ case SCMP_ARCH_MIPS:
+ return "mips";
+ case SCMP_ARCH_MIPS64:
+ return "mips64";
+ case SCMP_ARCH_MIPS64N32:
+ return "mips64-n32";
+ case SCMP_ARCH_MIPSEL:
+ return "mips-le";
+ case SCMP_ARCH_MIPSEL64:
+ return "mips64-le";
+ case SCMP_ARCH_MIPSEL64N32:
+ return "mips64-le-n32";
+ case SCMP_ARCH_PPC:
+ return "ppc";
+ case SCMP_ARCH_PPC64:
+ return "ppc64";
+ case SCMP_ARCH_PPC64LE:
+ return "ppc64-le";
+ case SCMP_ARCH_S390:
+ return "s390";
+ case SCMP_ARCH_S390X:
+ return "s390x";
+ default:
+ return NULL;
+ }
}
int seccomp_arch_from_string(const char *n, uint32_t *ret) {
@@ -57,60 +90,174 @@ int seccomp_arch_from_string(const char *n, uint32_t *ret) {
*ret = SCMP_ARCH_X32;
else if (streq(n, "arm"))
*ret = SCMP_ARCH_ARM;
+ else if (streq(n, "arm64"))
+ *ret = SCMP_ARCH_AARCH64;
+ else if (streq(n, "mips"))
+ *ret = SCMP_ARCH_MIPS;
+ else if (streq(n, "mips64"))
+ *ret = SCMP_ARCH_MIPS64;
+ else if (streq(n, "mips64-n32"))
+ *ret = SCMP_ARCH_MIPS64N32;
+ else if (streq(n, "mips-le"))
+ *ret = SCMP_ARCH_MIPSEL;
+ else if (streq(n, "mips64-le"))
+ *ret = SCMP_ARCH_MIPSEL64;
+ else if (streq(n, "mips64-le-n32"))
+ *ret = SCMP_ARCH_MIPSEL64N32;
+ else if (streq(n, "ppc"))
+ *ret = SCMP_ARCH_PPC;
+ else if (streq(n, "ppc64"))
+ *ret = SCMP_ARCH_PPC64;
+ else if (streq(n, "ppc64-le"))
+ *ret = SCMP_ARCH_PPC64LE;
+ else if (streq(n, "s390"))
+ *ret = SCMP_ARCH_S390;
+ else if (streq(n, "s390x"))
+ *ret = SCMP_ARCH_S390X;
else
return -EINVAL;
return 0;
}
-int seccomp_add_secondary_archs(scmp_filter_ctx *c) {
-
-#if defined(__i386__) || defined(__x86_64__)
+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 ctx) {
+
/* Add in all possible secondary archs we are aware of that
* this kernel might support. */
- r = seccomp_arch_add(c, SCMP_ARCH_X86);
- if (r < 0 && r != -EEXIST)
- return r;
+ static const int seccomp_arches[] = {
+#if defined(__i386__) || defined(__x86_64__)
+ SCMP_ARCH_X86,
+ SCMP_ARCH_X86_64,
+ SCMP_ARCH_X32,
- r = seccomp_arch_add(c, SCMP_ARCH_X86_64);
- if (r < 0 && r != -EEXIST)
- return r;
+#elif defined(__arm__) || defined(__aarch64__)
+ SCMP_ARCH_ARM,
+ SCMP_ARCH_AARCH64,
- r = seccomp_arch_add(c, SCMP_ARCH_X32);
- if (r < 0 && r != -EEXIST)
- return r;
+#elif defined(__arm__) || defined(__aarch64__)
+ SCMP_ARCH_ARM,
+ SCMP_ARCH_AARCH64,
+
+#elif defined(__mips__) || defined(__mips64__)
+ SCMP_ARCH_MIPS,
+ SCMP_ARCH_MIPS64,
+ SCMP_ARCH_MIPS64N32,
+ SCMP_ARCH_MIPSEL,
+ SCMP_ARCH_MIPSEL64,
+ SCMP_ARCH_MIPSEL64N32,
+
+#elif defined(__powerpc__) || defined(__powerpc64__)
+ SCMP_ARCH_PPC,
+ SCMP_ARCH_PPC64,
+ SCMP_ARCH_PPC64LE,
+#elif defined(__s390__) || defined(__s390x__)
+ SCMP_ARCH_S390,
+ SCMP_ARCH_S390X,
#endif
+ };
+
+ unsigned i;
+ int r;
+
+ for (i = 0; i < ELEMENTSOF(seccomp_arches); i++) {
+ r = seccomp_arch_add(ctx, seccomp_arches[i]);
+ if (r < 0 && r != -EEXIST)
+ return r;
+ }
return 0;
+}
+static bool is_basic_seccomp_available(void) {
+ int r;
+ r = prctl(PR_GET_SECCOMP, 0, 0, 0, 0);
+ return r >= 0;
}
-const SystemCallFilterSet syscall_filter_sets[] = {
- {
+static bool is_seccomp_filter_available(void) {
+ int r;
+ r = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, 0, 0);
+ return r < 0 && errno == EFAULT;
+}
+
+bool is_seccomp_available(void) {
+ static int cached_enabled = -1;
+ if (cached_enabled < 0)
+ cached_enabled = is_basic_seccomp_available() && is_seccomp_filter_available();
+ return cached_enabled;
+}
+
+const SyscallFilterSet syscall_filter_sets[_SYSCALL_FILTER_SET_MAX] = {
+ [SYSCALL_FILTER_SET_BASIC_IO] = {
+ /* Basic IO */
+ .name = "@basic-io",
+ .value =
+ "close\0"
+ "dup2\0"
+ "dup3\0"
+ "dup\0"
+ "lseek\0"
+ "pread64\0"
+ "preadv\0"
+ "pwrite64\0"
+ "pwritev\0"
+ "read\0"
+ "readv\0"
+ "write\0"
+ "writev\0"
+ },
+ [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"
@@ -118,20 +265,32 @@ 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"
- }, {
- /* Default list */
- .set_name = "@default",
+ },
+ [SYSCALL_FILTER_SET_DEFAULT] = {
+ /* Default list: the most basic of operations */
+ .name = "@default",
.value =
+ "clock_getres\0"
+ "clock_gettime\0"
+ "clock_nanosleep\0"
"execve\0"
"exit\0"
"exit_group\0"
+ "getrlimit\0" /* make sure processes can query stack size and such */
+ "gettimeofday\0"
+ "nanosleep\0"
+ "pause\0"
"rt_sigreturn\0"
"sigreturn\0"
- }, {
+ "time\0"
+ },
+ [SYSCALL_FILTER_SET_IO_EVENT] = {
/* Event loop use */
- .set_name = "@io-event",
+ .name = "@io-event",
.value =
"_newselect\0"
"epoll_create1\0"
@@ -147,10 +306,12 @@ const SystemCallFilterSet syscall_filter_sets[] = {
"ppoll\0"
"pselect6\0"
"select\0"
- }, {
- /* Message queues, SYSV IPC or other IPC: unusual */
- .set_name = "@ipc",
+ },
+ [SYSCALL_FILTER_SET_IPC] = {
+ /* Message queues, SYSV IPC or other IPC */
+ .name = "@ipc",
.value = "ipc\0"
+ "memfd_create\0"
"mq_getsetattr\0"
"mq_notify\0"
"mq_open\0"
@@ -161,6 +322,8 @@ const SystemCallFilterSet syscall_filter_sets[] = {
"msgget\0"
"msgrcv\0"
"msgsnd\0"
+ "pipe2\0"
+ "pipe\0"
"process_vm_readv\0"
"process_vm_writev\0"
"semctl\0"
@@ -171,33 +334,36 @@ 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"
@@ -220,9 +386,10 @@ 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"
@@ -248,9 +415,10 @@ 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"
@@ -287,15 +455,15 @@ 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"
- "execve\0"
"execveat\0"
"fork\0"
"kill\0"
@@ -305,19 +473,106 @@ 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
+ },
+ [SYSCALL_FILTER_SET_RESOURCES] = {
+ /* Alter resource settings */
+ .name = "@resources",
+ .value =
+ "sched_setparam\0"
+ "sched_setscheduler\0"
+ "sched_setaffinity\0"
+ "setpriority\0"
+ "setrlimit\0"
+ "set_mempolicy\0"
+ "migrate_pages\0"
+ "move_pages\0"
+ "mbind\0"
+ "sched_setattr\0"
+ "prlimit64\0"
+ },
};
+
+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;
+
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-16 03:18:21 +0000