From nobody Tue Nov 4 08:28:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1504263694603242.1326557845466; Fri, 1 Sep 2017 04:01:34 -0700 (PDT) Received: from localhost ([::1]:35188 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjhd-0002Kd-5w for importer@patchew.org; Fri, 01 Sep 2017 07:01:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51234) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjex-00006q-20 for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnjer-0001CM-3A for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45752) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dnjeq-0001Bz-RI for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:41 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C17747EA87 for ; Fri, 1 Sep 2017 10:58:39 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id BFC917E8EB; Fri, 1 Sep 2017 10:58:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C17747EA87 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:13 +0200 Message-Id: <20170901105818.31956-2-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 01 Sep 2017 10:58:39 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 1/6] seccomp: changing from whitelist to blacklist X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch changes the default behavior of the seccomp filter from whitelist to blacklist. By default now all system calls are allowed and a small black list of definitely forbidden ones was created. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 2 + qemu-seccomp.c | 264 ++++++-------------------------------------= ---- vl.c | 1 - 3 files changed, 35 insertions(+), 232 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index cfc06008cb..23b9c3c789 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -15,6 +15,8 @@ #ifndef QEMU_SECCOMP_H #define QEMU_SECCOMP_H =20 +#define QEMU_SECCOMP_SET_DEFAULT (1 << 0) + #include =20 int seccomp_start(void); diff --git a/qemu-seccomp.c b/qemu-seccomp.c index df75d9c471..585de42a97 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -28,232 +28,34 @@ =20 struct QemuSeccompSyscall { int32_t num; - uint8_t priority; + int type; + uint8_t set; }; =20 -static const struct QemuSeccompSyscall seccomp_whitelist[] =3D { - { SCMP_SYS(timer_settime), 255 }, - { SCMP_SYS(timer_gettime), 254 }, - { SCMP_SYS(futex), 253 }, - { SCMP_SYS(select), 252 }, - { SCMP_SYS(recvfrom), 251 }, - { SCMP_SYS(sendto), 250 }, - { SCMP_SYS(socketcall), 250 }, - { SCMP_SYS(read), 249 }, - { SCMP_SYS(io_submit), 249 }, - { SCMP_SYS(brk), 248 }, - { SCMP_SYS(clone), 247 }, - { SCMP_SYS(mmap), 247 }, - { SCMP_SYS(mprotect), 246 }, - { SCMP_SYS(execve), 245 }, - { SCMP_SYS(open), 245 }, - { SCMP_SYS(ioctl), 245 }, - { SCMP_SYS(socket), 245 }, - { SCMP_SYS(setsockopt), 245 }, - { SCMP_SYS(recvmsg), 245 }, - { SCMP_SYS(sendmsg), 245 }, - { SCMP_SYS(accept), 245 }, - { SCMP_SYS(connect), 245 }, - { SCMP_SYS(socketpair), 245 }, - { SCMP_SYS(bind), 245 }, - { SCMP_SYS(listen), 245 }, - { SCMP_SYS(semget), 245 }, - { SCMP_SYS(ipc), 245 }, - { SCMP_SYS(gettimeofday), 245 }, - { SCMP_SYS(readlink), 245 }, - { SCMP_SYS(access), 245 }, - { SCMP_SYS(prctl), 245 }, - { SCMP_SYS(signalfd), 245 }, - { SCMP_SYS(getrlimit), 245 }, - { SCMP_SYS(getrusage), 245 }, - { SCMP_SYS(set_tid_address), 245 }, - { SCMP_SYS(statfs), 245 }, - { SCMP_SYS(unlink), 245 }, - { SCMP_SYS(wait4), 245 }, - { SCMP_SYS(fcntl64), 245 }, - { SCMP_SYS(fstat64), 245 }, - { SCMP_SYS(stat64), 245 }, - { SCMP_SYS(getgid32), 245 }, - { SCMP_SYS(getegid32), 245 }, - { SCMP_SYS(getuid32), 245 }, - { SCMP_SYS(geteuid32), 245 }, - { SCMP_SYS(sigreturn), 245 }, - { SCMP_SYS(_newselect), 245 }, - { SCMP_SYS(_llseek), 245 }, - { SCMP_SYS(mmap2), 245 }, - { SCMP_SYS(sigprocmask), 245 }, - { SCMP_SYS(sched_getparam), 245 }, - { SCMP_SYS(sched_getscheduler), 245 }, - { SCMP_SYS(fstat), 245 }, - { SCMP_SYS(clock_getres), 245 }, - { SCMP_SYS(sched_get_priority_min), 245 }, - { SCMP_SYS(sched_get_priority_max), 245 }, - { SCMP_SYS(stat), 245 }, - { SCMP_SYS(uname), 245 }, - { SCMP_SYS(eventfd2), 245 }, - { SCMP_SYS(io_getevents), 245 }, - { SCMP_SYS(dup), 245 }, - { SCMP_SYS(dup2), 245 }, - { SCMP_SYS(dup3), 245 }, - { SCMP_SYS(gettid), 245 }, - { SCMP_SYS(getgid), 245 }, - { SCMP_SYS(getegid), 245 }, - { SCMP_SYS(getuid), 245 }, - { SCMP_SYS(geteuid), 245 }, - { SCMP_SYS(timer_create), 245 }, - { SCMP_SYS(times), 245 }, - { SCMP_SYS(exit), 245 }, - { SCMP_SYS(clock_gettime), 245 }, - { SCMP_SYS(time), 245 }, - { SCMP_SYS(restart_syscall), 245 }, - { SCMP_SYS(pwrite64), 245 }, - { SCMP_SYS(nanosleep), 245 }, - { SCMP_SYS(chown), 245 }, - { SCMP_SYS(openat), 245 }, - { SCMP_SYS(getdents), 245 }, - { SCMP_SYS(timer_delete), 245 }, - { SCMP_SYS(exit_group), 245 }, - { SCMP_SYS(rt_sigreturn), 245 }, - { SCMP_SYS(sync), 245 }, - { SCMP_SYS(pread64), 245 }, - { SCMP_SYS(madvise), 245 }, - { SCMP_SYS(set_robust_list), 245 }, - { SCMP_SYS(lseek), 245 }, - { SCMP_SYS(pselect6), 245 }, - { SCMP_SYS(fork), 245 }, - { SCMP_SYS(rt_sigprocmask), 245 }, - { SCMP_SYS(write), 244 }, - { SCMP_SYS(fcntl), 243 }, - { SCMP_SYS(tgkill), 242 }, - { SCMP_SYS(kill), 242 }, - { SCMP_SYS(rt_sigaction), 242 }, - { SCMP_SYS(pipe2), 242 }, - { SCMP_SYS(munmap), 242 }, - { SCMP_SYS(mremap), 242 }, - { SCMP_SYS(fdatasync), 242 }, - { SCMP_SYS(close), 242 }, - { SCMP_SYS(rt_sigpending), 242 }, - { SCMP_SYS(rt_sigtimedwait), 242 }, - { SCMP_SYS(readv), 242 }, - { SCMP_SYS(writev), 242 }, - { SCMP_SYS(preadv), 242 }, - { SCMP_SYS(pwritev), 242 }, - { SCMP_SYS(setrlimit), 242 }, - { SCMP_SYS(ftruncate), 242 }, - { SCMP_SYS(lstat), 242 }, - { SCMP_SYS(pipe), 242 }, - { SCMP_SYS(umask), 242 }, - { SCMP_SYS(chdir), 242 }, - { SCMP_SYS(setitimer), 242 }, - { SCMP_SYS(setsid), 242 }, - { SCMP_SYS(poll), 242 }, - { SCMP_SYS(epoll_create), 242 }, - { SCMP_SYS(epoll_ctl), 242 }, - { SCMP_SYS(epoll_wait), 242 }, - { SCMP_SYS(waitpid), 242 }, - { SCMP_SYS(getsockname), 242 }, - { SCMP_SYS(getpeername), 242 }, - { SCMP_SYS(accept4), 242 }, - { SCMP_SYS(timerfd_settime), 242 }, - { SCMP_SYS(newfstatat), 241 }, - { SCMP_SYS(shutdown), 241 }, - { SCMP_SYS(getsockopt), 241 }, - { SCMP_SYS(semop), 241 }, - { SCMP_SYS(semtimedop), 241 }, - { SCMP_SYS(epoll_ctl_old), 241 }, - { SCMP_SYS(epoll_wait_old), 241 }, - { SCMP_SYS(epoll_pwait), 241 }, - { SCMP_SYS(epoll_create1), 241 }, - { SCMP_SYS(ppoll), 241 }, - { SCMP_SYS(creat), 241 }, - { SCMP_SYS(link), 241 }, - { SCMP_SYS(getpid), 241 }, - { SCMP_SYS(getppid), 241 }, - { SCMP_SYS(getpgrp), 241 }, - { SCMP_SYS(getpgid), 241 }, - { SCMP_SYS(getsid), 241 }, - { SCMP_SYS(getdents64), 241 }, - { SCMP_SYS(getresuid), 241 }, - { SCMP_SYS(getresgid), 241 }, - { SCMP_SYS(getgroups), 241 }, - { SCMP_SYS(getresuid32), 241 }, - { SCMP_SYS(getresgid32), 241 }, - { SCMP_SYS(getgroups32), 241 }, - { SCMP_SYS(signal), 241 }, - { SCMP_SYS(sigaction), 241 }, - { SCMP_SYS(sigsuspend), 241 }, - { SCMP_SYS(sigpending), 241 }, - { SCMP_SYS(truncate64), 241 }, - { SCMP_SYS(ftruncate64), 241 }, - { SCMP_SYS(fchown32), 241 }, - { SCMP_SYS(chown32), 241 }, - { SCMP_SYS(lchown32), 241 }, - { SCMP_SYS(statfs64), 241 }, - { SCMP_SYS(fstatfs64), 241 }, - { SCMP_SYS(fstatat64), 241 }, - { SCMP_SYS(lstat64), 241 }, - { SCMP_SYS(sendfile64), 241 }, - { SCMP_SYS(ugetrlimit), 241 }, - { SCMP_SYS(alarm), 241 }, - { SCMP_SYS(rt_sigsuspend), 241 }, - { SCMP_SYS(rt_sigqueueinfo), 241 }, - { SCMP_SYS(rt_tgsigqueueinfo), 241 }, - { SCMP_SYS(sigaltstack), 241 }, - { SCMP_SYS(signalfd4), 241 }, - { SCMP_SYS(truncate), 241 }, - { SCMP_SYS(fchown), 241 }, - { SCMP_SYS(lchown), 241 }, - { SCMP_SYS(fchownat), 241 }, - { SCMP_SYS(fstatfs), 241 }, - { SCMP_SYS(getitimer), 241 }, - { SCMP_SYS(syncfs), 241 }, - { SCMP_SYS(fsync), 241 }, - { SCMP_SYS(fchdir), 241 }, - { SCMP_SYS(msync), 241 }, - { SCMP_SYS(sched_setparam), 241 }, - { SCMP_SYS(sched_setscheduler), 241 }, - { SCMP_SYS(sched_yield), 241 }, - { SCMP_SYS(sched_rr_get_interval), 241 }, - { SCMP_SYS(sched_setaffinity), 241 }, - { SCMP_SYS(sched_getaffinity), 241 }, - { SCMP_SYS(readahead), 241 }, - { SCMP_SYS(timer_getoverrun), 241 }, - { SCMP_SYS(unlinkat), 241 }, - { SCMP_SYS(readlinkat), 241 }, - { SCMP_SYS(faccessat), 241 }, - { SCMP_SYS(get_robust_list), 241 }, - { SCMP_SYS(splice), 241 }, - { SCMP_SYS(vmsplice), 241 }, - { SCMP_SYS(getcpu), 241 }, - { SCMP_SYS(sendmmsg), 241 }, - { SCMP_SYS(recvmmsg), 241 }, - { SCMP_SYS(prlimit64), 241 }, - { SCMP_SYS(waitid), 241 }, - { SCMP_SYS(io_cancel), 241 }, - { SCMP_SYS(io_setup), 241 }, - { SCMP_SYS(io_destroy), 241 }, - { SCMP_SYS(arch_prctl), 240 }, - { SCMP_SYS(mkdir), 240 }, - { SCMP_SYS(fchmod), 240 }, - { SCMP_SYS(shmget), 240 }, - { SCMP_SYS(shmat), 240 }, - { SCMP_SYS(shmdt), 240 }, - { SCMP_SYS(timerfd_create), 240 }, - { SCMP_SYS(shmctl), 240 }, - { SCMP_SYS(mlockall), 240 }, - { SCMP_SYS(mlock), 240 }, - { SCMP_SYS(munlock), 240 }, - { SCMP_SYS(semctl), 240 }, - { SCMP_SYS(fallocate), 240 }, - { SCMP_SYS(fadvise64), 240 }, - { SCMP_SYS(inotify_init1), 240 }, - { SCMP_SYS(inotify_add_watch), 240 }, - { SCMP_SYS(mbind), 240 }, - { SCMP_SYS(memfd_create), 240 }, -#ifdef HAVE_CACHEFLUSH - { SCMP_SYS(cacheflush), 240 }, -#endif - { SCMP_SYS(sysinfo), 240 }, +static const struct QemuSeccompSyscall blacklist[] =3D { + /* default set of syscalls to blacklist */ + { SCMP_SYS(reboot), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(swapon), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(swapoff), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(syslog), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(mount), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(umount), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(kexec_load), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(afs_syscall), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(break), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(ftime), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(getpmsg), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(gtty), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(lock), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(mpx), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(prof), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(profil), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(putpmsg), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(security), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(stty), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(tuxcall), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(ulimit), 1, QEMU_SECCOMP_SET_DEFAULT }, + { SCMP_SYS(vserver), 1, QEMU_SECCOMP_SET_DEFAULT }, }; =20 int seccomp_start(void) @@ -262,19 +64,19 @@ int seccomp_start(void) unsigned int i =3D 0; scmp_filter_ctx ctx; =20 - ctx =3D seccomp_init(SCMP_ACT_KILL); + ctx =3D seccomp_init(SCMP_ACT_ALLOW); if (ctx =3D=3D NULL) { rc =3D -1; goto seccomp_return; } =20 - for (i =3D 0; i < ARRAY_SIZE(seccomp_whitelist); i++) { - rc =3D seccomp_rule_add(ctx, SCMP_ACT_ALLOW, seccomp_whitelist[i].= num, 0); - if (rc < 0) { - goto seccomp_return; + for (i =3D 0; i < ARRAY_SIZE(blacklist); i++) { + switch (blacklist[i].set) { + default: + goto add_syscall; } - rc =3D seccomp_syscall_priority(ctx, seccomp_whitelist[i].num, - seccomp_whitelist[i].priority); +add_syscall: + rc =3D seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); if (rc < 0) { goto seccomp_return; } diff --git a/vl.c b/vl.c index 8e247cc2a2..305531aba8 100644 --- a/vl.c +++ b/vl.c @@ -1030,7 +1030,6 @@ static int bt_parse(const char *opt) =20 static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp) { - /* FIXME: change this to true for 1.3 */ if (qemu_opt_get_bool(opts, "enable", false)) { #ifdef CONFIG_SECCOMP if (seccomp_start() < 0) { --=20 2.13.5 From nobody Tue Nov 4 08:28:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1504263764950542.0931767183906; Fri, 1 Sep 2017 04:02:44 -0700 (PDT) Received: from localhost ([::1]:35197 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjil-0003KE-Qz for importer@patchew.org; Fri, 01 Sep 2017 07:02:43 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51251) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjey-00008G-Rj for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnjet-0001DD-QU for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37940) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dnjet-0001Cz-IH for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:43 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 854967E456 for ; Fri, 1 Sep 2017 10:58:42 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id 347A27E8EB; Fri, 1 Sep 2017 10:58:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 854967E456 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:14 +0200 Message-Id: <20170901105818.31956-3-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 01 Sep 2017 10:58:42 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 2/6] seccomp: add obsolete argument to command line X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch introduces the argument [,obsolete=3Dallow] to the `-sandbox on' option. It allows Qemu to run safely on old system that still relies on old system calls. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 3 ++- qemu-options.hx | 12 ++++++++++-- qemu-seccomp.c | 23 ++++++++++++++++++++++- vl.c | 22 +++++++++++++++++++++- 4 files changed, 55 insertions(+), 5 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index 23b9c3c789..215138a372 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -16,8 +16,9 @@ #define QEMU_SECCOMP_H =20 #define QEMU_SECCOMP_SET_DEFAULT (1 << 0) +#define QEMU_SECCOMP_SET_OBSOLETE (1 << 1) =20 #include =20 -int seccomp_start(void); +int seccomp_start(uint32_t seccomp_opts); #endif diff --git a/qemu-options.hx b/qemu-options.hx index 9f6e2adfff..72150c6b84 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4017,13 +4017,21 @@ Old param mode (ARM only). ETEXI =20 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ - "-sandbox Enable seccomp mode 2 system call filter (default 'of= f').\n", + "-sandbox on[,obsolete=3Dallow|deny]\n" \ + " Enable seccomp mode 2 system call filter (default 'of= f').\n" \ + " use 'obsolete' to allow obsolete system calls that ar= e provided\n" \ + " by the kernel, but typically no longer used by mo= dern\n" \ + " C library implementations.\n", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg} +@item -sandbox @var{arg}[,obsolete=3D@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filteri= ng and 'off' will disable it. The default is 'off'. +@table @option +@item obsolete=3D@var{string} +Enable Obsolete system calls +@end table ETEXI =20 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, diff --git a/qemu-seccomp.c b/qemu-seccomp.c index 585de42a97..3e3f15cc08 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -56,9 +56,22 @@ static const struct QemuSeccompSyscall blacklist[] =3D { { SCMP_SYS(tuxcall), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(ulimit), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(vserver), 1, QEMU_SECCOMP_SET_DEFAULT }, + /* obsolete */ + { SCMP_SYS(readdir), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(_sysctl), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(bdflush), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(create_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(get_kernel_syms), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(query_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(sgetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(ssetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(sysfs), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(uselib), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(ustat), 2, QEMU_SECCOMP_SET_OBSOLETE }, }; =20 -int seccomp_start(void) + +int seccomp_start(uint32_t seccomp_opts) { int rc =3D 0; unsigned int i =3D 0; @@ -72,6 +85,14 @@ int seccomp_start(void) =20 for (i =3D 0; i < ARRAY_SIZE(blacklist); i++) { switch (blacklist[i].set) { + case QEMU_SECCOMP_SET_OBSOLETE: + if (!(seccomp_opts & QEMU_SECCOMP_SET_OBSOLETE)) { + goto add_syscall; + } else { + continue; + } + + break; default: goto add_syscall; } diff --git a/vl.c b/vl.c index 305531aba8..ca267f9918 100644 --- a/vl.c +++ b/vl.c @@ -271,6 +271,10 @@ static QemuOptsList qemu_sandbox_opts =3D { .name =3D "enable", .type =3D QEMU_OPT_BOOL, }, + { + .name =3D "obsolete", + .type =3D QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1032,7 +1036,23 @@ static int parse_sandbox(void *opaque, QemuOpts *opt= s, Error **errp) { if (qemu_opt_get_bool(opts, "enable", false)) { #ifdef CONFIG_SECCOMP - if (seccomp_start() < 0) { + uint32_t seccomp_opts =3D 0x00000; + const char *value =3D NULL; + + value =3D qemu_opt_get(opts, "obsolete"); + if (value) { + if (strcmp(value, "allow") =3D=3D 0) { + seccomp_opts |=3D QEMU_SECCOMP_SET_OBSOLETE; + } else if (strcmp(value, "deny")) { + /* this is the default option, this if is here + * to provide a little bit of consistency for + * the command line */ + } else { + error_report("invalid argument for obsolete"); + } + } + + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); return -1; --=20 2.13.5 From nobody Tue Nov 4 08:28:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 150426362330062.202116384524516; Fri, 1 Sep 2017 04:00:23 -0700 (PDT) Received: from localhost ([::1]:35164 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjgU-0001CI-4P for importer@patchew.org; Fri, 01 Sep 2017 07:00:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51249) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjey-000089-MJ for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnjex-0001Gh-DL for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53852) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dnjex-0001E4-4Y for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:47 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 29F52356F4 for ; Fri, 1 Sep 2017 10:58:46 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id E00EF7E8EB; Fri, 1 Sep 2017 10:58:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 29F52356F4 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:15 +0200 Message-Id: <20170901105818.31956-4-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 01 Sep 2017 10:58:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 3/6] seccomp: add elevateprivileges argument to command line X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch introduces the new argument [,elevateprivileges=3Dallow|deny|children] to the `-sandbox on'. It allows or denies Qemu process to elevate its privileges by blacklisting all set*uid|gid system calls. The 'children' option will let forks and execves run unprivileged. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 1 + qemu-options.hx | 12 +++++++++--- qemu-seccomp.c | 29 ++++++++++++++++++----------- vl.c | 27 +++++++++++++++++++++++++++ 4 files changed, 55 insertions(+), 14 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index 215138a372..4a9e63c7cd 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -17,6 +17,7 @@ =20 #define QEMU_SECCOMP_SET_DEFAULT (1 << 0) #define QEMU_SECCOMP_SET_OBSOLETE (1 << 1) +#define QEMU_SECCOMP_SET_PRIVILEGED (1 << 2) =20 #include =20 diff --git a/qemu-options.hx b/qemu-options.hx index 72150c6b84..5c1b163fb5 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4017,20 +4017,26 @@ Old param mode (ARM only). ETEXI =20 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ - "-sandbox on[,obsolete=3Dallow|deny]\n" \ + "-sandbox on[,obsolete=3Dallow|deny][,elevateprivileges=3Dallow|deny|c= hildren]\n" \ " Enable seccomp mode 2 system call filter (default 'of= f').\n" \ " use 'obsolete' to allow obsolete system calls that ar= e provided\n" \ " by the kernel, but typically no longer used by mo= dern\n" \ - " C library implementations.\n", + " C library implementations.\n" \ + " use 'elevateprivileges' to allow or deny QEMU process= to elevate\n" \ + " its privileges by blacklisting all set*uid|gid sy= stem calls.\n" \ + " The value 'children' will deny set*uid|gid system= calls for\n" \ + " main QEMU process but will allow forks and execve= s to run unprivileged\n", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg}[,obsolete=3D@var{string}] +@item -sandbox @var{arg}[,obsolete=3D@var{string}][,elevateprivileges=3D@v= ar{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filteri= ng and 'off' will disable it. The default is 'off'. @table @option @item obsolete=3D@var{string} Enable Obsolete system calls +@item elevateprivileges=3D@var{string} +Disable set*uid|gid system calls @end table ETEXI =20 diff --git a/qemu-seccomp.c b/qemu-seccomp.c index 3e3f15cc08..16c8c20132 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -57,17 +57,16 @@ static const struct QemuSeccompSyscall blacklist[] =3D { { SCMP_SYS(ulimit), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(vserver), 1, QEMU_SECCOMP_SET_DEFAULT }, /* obsolete */ - { SCMP_SYS(readdir), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(_sysctl), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(bdflush), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(create_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(get_kernel_syms), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(query_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(sgetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(ssetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(sysfs), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(uselib), 2, QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(ustat), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(setuid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setgid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setpgid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setsid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setreuid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setregid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setresuid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setresgid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setfsuid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + { SCMP_SYS(setfsgid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, }; =20 =20 @@ -93,6 +92,14 @@ int seccomp_start(uint32_t seccomp_opts) } =20 break; + case QEMU_SECCOMP_SET_PRIVILEGED: + if (seccomp_opts & QEMU_SECCOMP_SET_PRIVILEGED) { + goto add_syscall; + } else { + continue; + } + + break; default: goto add_syscall; } diff --git a/vl.c b/vl.c index ca267f9918..1d44b05772 100644 --- a/vl.c +++ b/vl.c @@ -29,6 +29,7 @@ =20 #ifdef CONFIG_SECCOMP #include "sysemu/seccomp.h" +#include "sys/prctl.h" #endif =20 #if defined(CONFIG_VDE) @@ -275,6 +276,10 @@ static QemuOptsList qemu_sandbox_opts =3D { .name =3D "obsolete", .type =3D QEMU_OPT_STRING, }, + { + .name =3D "elevateprivileges", + .type =3D QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1052,6 +1057,28 @@ static int parse_sandbox(void *opaque, QemuOpts *opt= s, Error **errp) } } =20 + value =3D qemu_opt_get(opts, "elevateprivileges"); + if (value) { + if (strcmp(value, "deny") =3D=3D 0) { + seccomp_opts |=3D QEMU_SECCOMP_SET_PRIVILEGED; + } else if (strcmp(value, "children") =3D=3D 0) { + seccomp_opts |=3D QEMU_SECCOMP_SET_PRIVILEGED; + + /* calling prctl directly because we're + * not sure if host has CAP_SYS_ADMIN set*/ + if (prctl(PR_SET_NO_NEW_PRIVS, 1)) { + error_report("failed to set no_new_privs " + "aborting"); + return -1; + } + } else if (strcmp(value, "allow") =3D=3D 0) { + /* default value */ + } else { + error_report("invalid argument for elevateprivileges"); + return -1; + } + } + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); --=20 2.13.5 From nobody Tue Nov 4 08:28:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1504263784575389.72547533599425; 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Fri, 1 Sep 2017 10:58:51 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id DAD2D7EBC7; Fri, 1 Sep 2017 10:58:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 6A91961483 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:16 +0200 Message-Id: <20170901105818.31956-5-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 01 Sep 2017 10:58:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 4/6] seccomp: add spawn argument to command line X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch adds [,spawn=3Ddeny] argument to `-sandbox on' option. It blacklists fork and execve system calls, avoiding Qemu to spawn new threads or processes. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 1 + qemu-options.hx | 9 +++++++-- qemu-seccomp.c | 12 ++++++++++++ vl.c | 16 ++++++++++++++++ 4 files changed, 36 insertions(+), 2 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index 4a9e63c7cd..3ab5fc4f61 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -18,6 +18,7 @@ #define QEMU_SECCOMP_SET_DEFAULT (1 << 0) #define QEMU_SECCOMP_SET_OBSOLETE (1 << 1) #define QEMU_SECCOMP_SET_PRIVILEGED (1 << 2) +#define QEMU_SECCOMP_SET_SPAWN (1 << 3) =20 #include =20 diff --git a/qemu-options.hx b/qemu-options.hx index 5c1b163fb5..2b04b9f170 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4018,6 +4018,7 @@ ETEXI =20 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ "-sandbox on[,obsolete=3Dallow|deny][,elevateprivileges=3Dallow|deny|c= hildren]\n" \ + " [,spawn=3Dallow|deny]\n" \ " Enable seccomp mode 2 system call filter (default 'of= f').\n" \ " use 'obsolete' to allow obsolete system calls that ar= e provided\n" \ " by the kernel, but typically no longer used by mo= dern\n" \ @@ -4025,10 +4026,12 @@ DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ " use 'elevateprivileges' to allow or deny QEMU process= to elevate\n" \ " its privileges by blacklisting all set*uid|gid sy= stem calls.\n" \ " The value 'children' will deny set*uid|gid system= calls for\n" \ - " main QEMU process but will allow forks and execve= s to run unprivileged\n", + " main QEMU process but will allow forks and execve= s to run unprivileged\n" \ + " use 'spawn' to avoid QEMU to spawn new threads or pro= cesses by\n" \ + " blacklisting *fork and execve\n", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg}[,obsolete=3D@var{string}][,elevateprivileges=3D@v= ar{string}] +@item -sandbox @var{arg}[,obsolete=3D@var{string}][,elevateprivileges=3D@v= ar{string}][,spawn=3D@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filteri= ng and 'off' will disable it. The default is 'off'. @@ -4037,6 +4040,8 @@ disable it. The default is 'off'. Enable Obsolete system calls @item elevateprivileges=3D@var{string} Disable set*uid|gid system calls +@item spawn=3D@var{string} +Disable *fork and execve @end table ETEXI =20 diff --git a/qemu-seccomp.c b/qemu-seccomp.c index 16c8c20132..51754ace71 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -67,6 +67,10 @@ static const struct QemuSeccompSyscall blacklist[] =3D { { SCMP_SYS(setresgid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, { SCMP_SYS(setfsuid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, { SCMP_SYS(setfsgid), 4, QEMU_SECCOMP_SET_PRIVILEGED }, + /* spawn */ + { SCMP_SYS(fork), 8, QEMU_SECCOMP_SET_SPAWN }, + { SCMP_SYS(vfork), 8, QEMU_SECCOMP_SET_SPAWN }, + { SCMP_SYS(execve), 8, QEMU_SECCOMP_SET_SPAWN }, }; =20 =20 @@ -100,6 +104,14 @@ int seccomp_start(uint32_t seccomp_opts) } =20 break; + case QEMU_SECCOMP_SET_SPAWN: + if (seccomp_opts & QEMU_SECCOMP_SET_SPAWN) { + goto add_syscall; + } else { + continue; + } + + break; default: goto add_syscall; } diff --git a/vl.c b/vl.c index 1d44b05772..8e6b252f8f 100644 --- a/vl.c +++ b/vl.c @@ -280,6 +280,10 @@ static QemuOptsList qemu_sandbox_opts =3D { .name =3D "elevateprivileges", .type =3D QEMU_OPT_STRING, }, + { + .name =3D "spawn", + .type =3D QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1079,6 +1083,18 @@ static int parse_sandbox(void *opaque, QemuOpts *opt= s, Error **errp) } } =20 + value =3D qemu_opt_get(opts, "spawn"); + if (value) { + if (strcmp(value, "deny") =3D=3D 0) { + seccomp_opts |=3D QEMU_SECCOMP_SET_SPAWN; + } else if (strcmp(value, "allow") =3D=3D 0) { + /* default value */ + } else { + error_report("invalid argument for spawn"); + return -1; + } + } + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); --=20 2.13.5 From nobody Tue Nov 4 08:28:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1504263878093823.2062098388488; Fri, 1 Sep 2017 04:04:38 -0700 (PDT) Received: from localhost ([::1]:35225 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjka-0004vB-N0 for importer@patchew.org; Fri, 01 Sep 2017 07:04:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51348) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjfD-0000MN-0i for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:59:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnjf8-0001QV-6X for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:59:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4049) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dnjf7-0001PX-UC for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:58 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E72ACC0467D7 for ; Fri, 1 Sep 2017 10:58:56 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8A8D97E5D2; Fri, 1 Sep 2017 10:58:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E72ACC0467D7 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:17 +0200 Message-Id: <20170901105818.31956-6-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 01 Sep 2017 10:58:57 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 5/6] seccomp: add resourcecontrol argument to command line X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch adds [,resourcecontrol=3Ddeny] to `-sandbox on' option. It blacklists all process affinity and scheduler priority system calls to avoid any bigger of the process. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 1 + qemu-options.hx | 9 ++++++--- qemu-seccomp.c | 19 +++++++++++++++++++ vl.c | 16 ++++++++++++++++ 4 files changed, 42 insertions(+), 3 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index 3ab5fc4f61..e67c2dc840 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -19,6 +19,7 @@ #define QEMU_SECCOMP_SET_OBSOLETE (1 << 1) #define QEMU_SECCOMP_SET_PRIVILEGED (1 << 2) #define QEMU_SECCOMP_SET_SPAWN (1 << 3) +#define QEMU_SECCOMP_SET_RESOURCECTL (1 << 4) =20 #include =20 diff --git a/qemu-options.hx b/qemu-options.hx index 2b04b9f170..600614f6e5 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4018,7 +4018,7 @@ ETEXI =20 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ "-sandbox on[,obsolete=3Dallow|deny][,elevateprivileges=3Dallow|deny|c= hildren]\n" \ - " [,spawn=3Dallow|deny]\n" \ + " [,spawn=3Dallow|deny][,resourcecontrol=3Dallow|deny]\n" \ " Enable seccomp mode 2 system call filter (default 'of= f').\n" \ " use 'obsolete' to allow obsolete system calls that ar= e provided\n" \ " by the kernel, but typically no longer used by mo= dern\n" \ @@ -4028,10 +4028,11 @@ DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ " The value 'children' will deny set*uid|gid system= calls for\n" \ " main QEMU process but will allow forks and execve= s to run unprivileged\n" \ " use 'spawn' to avoid QEMU to spawn new threads or pro= cesses by\n" \ - " blacklisting *fork and execve\n", + " blacklisting *fork and execve\n" \ + " use 'resourcecontrol' to disable process affinity and= schedular priority\n", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg}[,obsolete=3D@var{string}][,elevateprivileges=3D@v= ar{string}][,spawn=3D@var{string}] +@item -sandbox @var{arg}[,obsolete=3D@var{string}][,elevateprivileges=3D@v= ar{string}][,spawn=3D@var{string}][,resourcecontrol=3D@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filteri= ng and 'off' will disable it. The default is 'off'. @@ -4042,6 +4043,8 @@ Enable Obsolete system calls Disable set*uid|gid system calls @item spawn=3D@var{string} Disable *fork and execve +@item resourcecontrol=3D@var{string} +Disable process affinity and schedular priority @end table ETEXI =20 diff --git a/qemu-seccomp.c b/qemu-seccomp.c index 51754ace71..ae787a4312 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -71,6 +71,17 @@ static const struct QemuSeccompSyscall blacklist[] =3D { { SCMP_SYS(fork), 8, QEMU_SECCOMP_SET_SPAWN }, { SCMP_SYS(vfork), 8, QEMU_SECCOMP_SET_SPAWN }, { SCMP_SYS(execve), 8, QEMU_SECCOMP_SET_SPAWN }, + /* resource control */ + { SCMP_SYS(getpriority), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(setpriority), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_setparam), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_getparam), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_setscheduler), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_getscheduler), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_setaffinity), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_getaffinity), 16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_get_priority_max),16, QEMU_SECCOMP_SET_RESOURCECTL }, + { SCMP_SYS(sched_get_priority_min),16, QEMU_SECCOMP_SET_RESOURCECTL }, }; =20 =20 @@ -112,6 +123,14 @@ int seccomp_start(uint32_t seccomp_opts) } =20 break; + case QEMU_SECCOMP_SET_RESOURCECTL: + if (seccomp_opts & QEMU_SECCOMP_SET_RESOURCECTL) { + goto add_syscall; + } else { + continue; + } + + break; default: goto add_syscall; } diff --git a/vl.c b/vl.c index 8e6b252f8f..563e7206ac 100644 --- a/vl.c +++ b/vl.c @@ -284,6 +284,10 @@ static QemuOptsList qemu_sandbox_opts =3D { .name =3D "spawn", .type =3D QEMU_OPT_STRING, }, + { + .name =3D "resourcecontrol", + .type =3D QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1095,6 +1099,18 @@ static int parse_sandbox(void *opaque, QemuOpts *opt= s, Error **errp) } } =20 + value =3D qemu_opt_get(opts, "resourcecontrol"); + if (value) { + if (strcmp(value, "deny") =3D=3D 0) { + seccomp_opts |=3D QEMU_SECCOMP_SET_RESOURCECTL; + } else if (strcmp(value, "allow") =3D=3D 0) { + /* default value */ + } else { + error_report("invalid argument for resourcecontrol"); + return -1; + } + } + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); --=20 2.13.5 From nobody Tue Nov 4 08:28:27 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1504263937618490.8850922073534; Fri, 1 Sep 2017 04:05:37 -0700 (PDT) Received: from localhost ([::1]:35285 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjlY-0005qM-BX for importer@patchew.org; Fri, 01 Sep 2017 07:05:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51335) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjfB-0000Kk-1B for qemu-devel@nongnu.org; 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dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:18 +0200 Message-Id: <20170901105818.31956-7-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 01 Sep 2017 10:58:59 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 6/6] seccomp: adding documentation to new seccomp model X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Adding new documentation under docs/ to describe every one and each new option added by the refactoring patchset. Signed-off-by: Eduardo Otubo --- docs/seccomp.txt | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 docs/seccomp.txt diff --git a/docs/seccomp.txt b/docs/seccomp.txt new file mode 100644 index 0000000000..a5eca85a9b --- /dev/null +++ b/docs/seccomp.txt @@ -0,0 +1,31 @@ +QEMU Seccomp system call filter +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D + +Starting from QEMU version 2.11, the seccomp filter does not work as a +whitelist but as a blacklist instead. This method allows safer deploys sin= ce +only the strictly forbidden system calls will be black-listed and the +possibility of breaking any workload is close to zero. + +The default option (-sandbox on) has a slightly looser security though and= the +reason is that it shouldn't break any backwards compatibility with previous +deploys and command lines already running. But if the intent is to have a +better security from this version on, one should make use of the following +additional options properly: + +* obsolete=3Dallow|deny: It allows Qemu to run safely on old system that s= till + relies on old system calls. + +* elevateprivileges=3Dallow|deny|children: It allows or denies Qemu process + to elevate its privileges by blacklisting all set*uid|gid system calls. = The + 'children' option sets the PR_SET_NO_NEW_PRIVS to 1 which allows helpers + (forks and execs) to run unprivileged. + +* spawn=3Dallow|deny: It blacklists fork and execve system calls, avoiding= QEMU to + spawn new threads or processes. + +* resourcecontrol=3Dallow|deny: It blacklists all process affinity and sch= eduler + priority system calls to avoid that the process can increase its amount = of + allowed resource consumption. + +-- +Eduardo Otubo --=20 2.13.5