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[Qemu-devel] [PATCH 5/6] seccomp: add resourcecontrol argument to comman
From: |
Eduardo Otubo |
Subject: |
[Qemu-devel] [PATCH 5/6] seccomp: add resourcecontrol argument to command line |
Date: |
Fri, 14 Jul 2017 13:36:59 +0200 |
This patch adds [,resourcecontrol=deny] 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 <address@hidden>
---
include/sysemu/seccomp.h | 1 +
qemu-options.hx | 5 ++++-
qemu-seccomp.c | 27 +++++++++++++++++++++++++++
vl.c | 11 +++++++++++
4 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h
index f1614d6514..c7003dd197 100644
--- a/include/sysemu/seccomp.h
+++ b/include/sysemu/seccomp.h
@@ -18,6 +18,7 @@
#define OBSOLETE 0x0001
#define PRIVILEGED 0x0010
#define SPAWN 0x0100
+#define RESOURCECTL 0x1000
#include <seccomp.h>
diff --git a/qemu-options.hx b/qemu-options.hx
index 611a501684..77b437a052 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4004,11 +4004,12 @@ Old param mode (ARM only).
ETEXI
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
- "-sandbox
on[,obsolete=allow][,elevateprivileges=allow|deny|children][,spawn=deny]\n" \
+ "-sandbox
on[,obsolete=allow][,elevateprivileges=allow|deny|children][,spawn=deny][,resourcecontrol=deny]\n"
\
" Enable seccomp mode 2 system call filter
(default 'off').\n" \
" obsolete: Allow obsolete system calls\n" \
" elevateprivileges: allows or denies Qemu
process to elevate its privileges by blacklisting all set*uid|gid system calls.
'children' will deny set*uid|gid system calls for main Qemu process but will
allow forks and execves to run unprivileged",
" spawn: avoids Qemu to spawn new threads or
processes by blacklisting *fork and execve\n"
+ " resourcecontrol: disable process affinity
and schedular priority\n",
QEMU_ARCH_ALL)
STEXI
@item -sandbox @var{arg}[,address@hidden
@@ -4022,6 +4023,8 @@ Enable Obsolete system calls
Disable set*uid|gid systema calls
@item address@hidden
Disable *fork and execve
address@hidden address@hidden
+Disable process affinity and schedular priority
@end table
ETEXI
diff --git a/qemu-seccomp.c b/qemu-seccomp.c
index 075d87e27f..a9a35456e9 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -31,6 +31,19 @@ struct QemuSeccompSyscall {
uint8_t priority;
};
+static const struct QemuSeccompSyscall resourcecontrol_syscalls[] = {
+ { SCMP_SYS(getpriority), 255 },
+ { SCMP_SYS(setpriority), 255 },
+ { SCMP_SYS(sched_setparam), 255 },
+ { SCMP_SYS(sched_getparam), 255 },
+ { SCMP_SYS(sched_setscheduler), 255 },
+ { SCMP_SYS(sched_getscheduler), 255 },
+ { SCMP_SYS(sched_setaffinity), 255 },
+ { SCMP_SYS(sched_getaffinity), 255 },
+ { SCMP_SYS(sched_get_priority_max), 255 },
+ { SCMP_SYS(sched_get_priority_min), 255 },
+};
+
static const struct QemuSeccompSyscall spawn_syscalls[] = {
{ SCMP_SYS(fork), 255 },
{ SCMP_SYS(vfork), 255 },
@@ -158,6 +171,20 @@ int seccomp_start(uint8_t seccomp_opts)
}
}
+ if (seccomp_opts & RESOURCECTL) {
+ for (i = 0; i < ARRAY_SIZE(resourcecontrol_syscalls); i++) {
+ rc = seccomp_rule_add(ctx, SCMP_ACT_KILL,
resourcecontrol_syscalls[i].num, 0);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ rc = seccomp_syscall_priority(ctx, resourcecontrol_syscalls[i].num,
+ resourcecontrol_syscalls[i].priority);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ }
+ }
+
rc = seccomp_load(ctx);
seccomp_return:
diff --git a/vl.c b/vl.c
index 456a518431..8e92052603 100644
--- a/vl.c
+++ b/vl.c
@@ -283,6 +283,10 @@ static QemuOptsList qemu_sandbox_opts = {
.name = "spawn",
.type = QEMU_OPT_STRING,
},
+ {
+ .name = "resourcecontrol",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1075,6 +1079,13 @@ static int parse_sandbox(void *opaque, QemuOpts *opts,
Error **errp)
}
}
+ value = qemu_opt_get(opts,"resourcecontrol");
+ if (value) {
+ if (strcmp(value, "deny") == 0) {
+ seccomp_opts |= RESOURCECTL;
+ }
+ }
+
if (seccomp_start(seccomp_opts) < 0) {
error_report("failed to install seccomp syscall filter "
"in the kernel");
--
2.13.0
- [Qemu-devel] [PATCH 0/6] seccomp: feature refactoring, Eduardo Otubo, 2017/07/14
- [Qemu-devel] [PATCH 2/6] seccomp: add obsolete argument to command line, Eduardo Otubo, 2017/07/14
- [Qemu-devel] [PATCH 1/6] seccomp: changing from whitelist to blacklist, Eduardo Otubo, 2017/07/14
- [Qemu-devel] [PATCH 3/6] seccomp: add elevateprivileges argument to command line, Eduardo Otubo, 2017/07/14
- [Qemu-devel] [PATCH 4/6] seccomp: add spawn argument to command line, Eduardo Otubo, 2017/07/14
- [Qemu-devel] [PATCH 6/6] seccomp: adding documentation to new seccomp model, Eduardo Otubo, 2017/07/14
- [Qemu-devel] [PATCH 5/6] seccomp: add resourcecontrol argument to command line,
Eduardo Otubo <=
- Re: [Qemu-devel] [PATCH 0/6] seccomp: feature refactoring, no-reply, 2017/07/14
- Re: [Qemu-devel] [PATCH 0/6] seccomp: feature refactoring, no-reply, 2017/07/14
- Re: [Qemu-devel] [PATCH 0/6] seccomp: feature refactoring, no-reply, 2017/07/14