9:49 a.m.
If QEMU uses a seccomp blacklist (since 2.11), -sandbox on
no longer tries to whitelist all the calls, but uses sets
of blacklists:
default (always blacklisted with -sandbox on)
obsolete (defaults to deny)
elevateprivileges (setuid & co, default: allow)
spawn (fork & execve, default: allow)
resourcecontrol (setaffinity, setscheduler, default: allow)
If these are supported, default to sandbox with all four
categories blacklisted.
https://bugzilla.redhat.com/show_bug.cgi?id=1492597
Signed-off-by: Ján Tomko <jtomko(a)redhat.com>
---
src/qemu/qemu.conf | 7 +++---
src/qemu/qemu_command.c | 10 +++++++++
tests/qemuxml2argvdata/minimal-sandbox.args | 29 ++++++++++++++++++++++++
tests/qemuxml2argvdata/minimal-sandbox.xml | 34 +++++++++++++++++++++++++++++
tests/qemuxml2argvtest.c | 11 ++++++++++
5 files changed, 88 insertions(+), 3 deletions(-)
create mode 100644 tests/qemuxml2argvdata/minimal-sandbox.args
create mode 100644 tests/qemuxml2argvdata/minimal-sandbox.xml
diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf
index 07eab7eff..740129cf5 100644
--- a/src/qemu/qemu.conf
+++ b/src/qemu/qemu.conf
@@ -669,9 +669,10 @@
-# Use seccomp syscall whitelisting in QEMU.
-# 1 = on, 0 = off, -1 = use QEMU default
-# Defaults to -1.
+# Use seccomp syscall sandbox in QEMU.
+# 1 = on, 0 = off, -1 = use the default
+# For QEMUs using a whitelist, the default (-1) is off.
+# For QEMUs using a blacklist, the default (-1) is on.
#
#seccomp_sandbox = 1
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index ba279e640..fa5906d0b 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -9987,6 +9987,16 @@ qemuBuildSeccompSandboxCommandLine(virCommandPtr cmd,
return 0;
}
+ /* Use blacklist by default if supported */
+ if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_SECCOMP_BLACKLIST)) {
+ virCommandAddArgList(cmd, "-sandbox",
+ "on,obsolete=deny,elevateprivileges=deny,"
+ "spawn=deny,resourcecontrol=deny",
+ NULL);
+ return 0;
+ }
+
+ /* Seccomp whitelist is opt-in */
if (cfg->seccompSandbox > 0)
virCommandAddArgList(cmd, "-sandbox", "on", NULL);
diff --git a/tests/qemuxml2argvdata/minimal-sandbox.args
b/tests/qemuxml2argvdata/minimal-sandbox.args
new file mode 100644
index 000000000..c9d71fe8f
--- /dev/null
+++ b/tests/qemuxml2argvdata/minimal-sandbox.args
@@ -0,0 +1,29 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-i686 \
+-name QEMUGuest1 \
+-S \
+-machine pc,accel=tcg,usb=off,dump-guest-core=off \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-QEMUGuest1/monitor.sock,\
+server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot c \
+-usb \
+-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
+-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
+resourcecontrol=deny
diff --git a/tests/qemuxml2argvdata/minimal-sandbox.xml
b/tests/qemuxml2argvdata/minimal-sandbox.xml
new file mode 100644
index 000000000..9ef92f8fe
--- /dev/null
+++ b/tests/qemuxml2argvdata/minimal-sandbox.xml
@@ -0,0 +1,34 @@
+<domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <title>A description of the test machine.</title>
+ <description>
+ A test of qemu's minimal configuration.
+ This test also tests the description and title elements.
+ </description>
+ <memory unit='KiB'>219100</memory>
+ <currentMemory unit='KiB'>219100</currentMemory>
+ <vcpu placement='static' cpuset='1-4,8-20,525'>1</vcpu>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-i686</emulator>
+ <disk type='block' device='disk'>
+ <source dev='/dev/HostVG/QEMUGuest1'/>
+ <target dev='hda' bus='ide'/>
+ <address type='drive' controller='0' bus='0'
target='0' unit='0'/>
+ </disk>
+ <controller type='usb' index='0'/>
+ <controller type='ide' index='0'/>
+ <controller type='pci' index='0' model='pci-root'/>
+ <input type='mouse' bus='ps2'/>
+ <input type='keyboard' bus='ps2'/>
+ <memballoon model='virtio'/>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 9a22fe5f4..cf69135e8 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -729,6 +729,17 @@ mymain(void)
unsetenv("SDL_AUDIODRIVER");
DO_TEST("minimal", NONE);
+ DO_TEST("minimal-sandbox",
+ QEMU_CAPS_MACHINE_OPT,
+ QEMU_CAPS_MONITOR_JSON,
+ QEMU_CAPS_NO_USER_CONFIG,
+ QEMU_CAPS_RTC,
+ QEMU_CAPS_NO_SHUTDOWN,
+ QEMU_CAPS_DUMP_GUEST_CORE,
+ QEMU_CAPS_DISPLAY,
+ QEMU_CAPS_MACHINE_USB_OPT,
+ QEMU_CAPS_SECCOMP_SANDBOX,
+ QEMU_CAPS_SECCOMP_BLACKLIST);
DO_TEST_PARSE_ERROR("minimal-no-memory", NONE);
DO_TEST("minimal-msg-timestamp", QEMU_CAPS_MSG_TIMESTAMP);
DO_TEST("machine-aliases1", NONE);
--
2.16.1