| /* |
| * QEMU seccomp mode 2 support with libseccomp |
| * |
| * Copyright IBM, Corp. 2012 |
| * |
| * Authors: |
| * Eduardo Otubo <eotubo@br.ibm.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| * |
| * Contributions after 2012-01-13 are licensed under the terms of the |
| * GNU GPL, version 2 or (at your option) any later version. |
| */ |
| #include "qemu/osdep.h" |
| #include <seccomp.h> |
| #include "sysemu/seccomp.h" |
| |
| /* For some architectures (notably ARM) cacheflush is not supported until |
| * libseccomp 2.2.3, but configure enforces that we are using a more recent |
| * version on those hosts, so it is OK for this check to be less strict. |
| */ |
| #if SCMP_VER_MAJOR >= 3 |
| #define HAVE_CACHEFLUSH |
| #elif SCMP_VER_MAJOR == 2 && SCMP_VER_MINOR >= 2 |
| #define HAVE_CACHEFLUSH |
| #endif |
| |
| struct QemuSeccompSyscall { |
| int32_t num; |
| uint8_t set; |
| }; |
| |
| static const struct QemuSeccompSyscall blacklist[] = { |
| /* default set of syscalls to blacklist */ |
| { SCMP_SYS(reboot), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(swapon), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(swapoff), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(syslog), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(mount), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(umount), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(kexec_load), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(afs_syscall), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(break), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(ftime), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(getpmsg), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(gtty), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(lock), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(mpx), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(prof), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(profil), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(putpmsg), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(security), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(stty), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(tuxcall), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(ulimit), QEMU_SECCOMP_SET_DEFAULT }, |
| { SCMP_SYS(vserver), QEMU_SECCOMP_SET_DEFAULT }, |
| /* obsolete */ |
| { SCMP_SYS(readdir), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(_sysctl), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(bdflush), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(create_module), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(get_kernel_syms), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(query_module), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(sgetmask), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(ssetmask), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(sysfs), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(uselib), QEMU_SECCOMP_SET_OBSOLETE }, |
| { SCMP_SYS(ustat), QEMU_SECCOMP_SET_OBSOLETE }, |
| /* privileged */ |
| { SCMP_SYS(setuid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setgid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setpgid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setsid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setreuid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setregid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setresuid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setresgid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setfsuid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| { SCMP_SYS(setfsgid), QEMU_SECCOMP_SET_PRIVILEGED }, |
| /* spawn */ |
| { SCMP_SYS(fork), QEMU_SECCOMP_SET_SPAWN }, |
| { SCMP_SYS(vfork), QEMU_SECCOMP_SET_SPAWN }, |
| { SCMP_SYS(execve), QEMU_SECCOMP_SET_SPAWN }, |
| }; |
| |
| |
| int seccomp_start(uint32_t seccomp_opts) |
| { |
| int rc = 0; |
| unsigned int i = 0; |
| scmp_filter_ctx ctx; |
| |
| ctx = seccomp_init(SCMP_ACT_ALLOW); |
| if (ctx == NULL) { |
| rc = -1; |
| goto seccomp_return; |
| } |
| |
| for (i = 0; i < ARRAY_SIZE(blacklist); i++) { |
| if (!(seccomp_opts & blacklist[i].set)) { |
| continue; |
| } |
| |
| rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); |
| if (rc < 0) { |
| goto seccomp_return; |
| } |
| } |
| |
| rc = seccomp_load(ctx); |
| |
| seccomp_return: |
| seccomp_release(ctx); |
| return rc; |
| } |