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 <ot...@redhat.com>
---
include/sysemu/seccomp.h | 1 +
qemu-options.hx | 9 ++++++---
qemu-seccomp.c | 11 +++++++++++
vl.c | 16 ++++++++++++++++
4 files changed, 34 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)
#include <seccomp.h>
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
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
"-sandbox
on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\n" \
- " [,spawn=allow|deny]\n" \
+ " [,spawn=allow|deny][,resourcecontrol=allow|deny]\n" \
" Enable seccomp mode 2 system call filter (default
'off').\n" \
" use 'obsolete' to allow obsolete system calls that are
provided\n" \
" by the kernel, but typically no longer used by
modern\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 execves to
run unprivileged\n" \
" use 'spawn' to avoid QEMU to spawn new threads or
processes 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=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}]
+@item -sandbox
@var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@var{string}]
@findex -sandbox
Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering
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=@var{string}
Disable *fork and execve
+@item resourcecontrol=@var{string}
+Disable process affinity and schedular priority
@end table
ETEXI
diff --git a/qemu-seccomp.c b/qemu-seccomp.c
index f3878a5e29..b770a77d33 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -82,6 +82,17 @@ static const struct QemuSeccompSyscall blacklist[] = {
{ SCMP_SYS(fork), QEMU_SECCOMP_SET_SPAWN },
{ SCMP_SYS(vfork), QEMU_SECCOMP_SET_SPAWN },
{ SCMP_SYS(execve), QEMU_SECCOMP_SET_SPAWN },
+ /* resource control */
+ { SCMP_SYS(getpriority), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(setpriority), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_setparam), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_getparam), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_setscheduler), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_getscheduler), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_setaffinity), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_getaffinity), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_get_priority_max), QEMU_SECCOMP_SET_RESOURCECTL },
+ { SCMP_SYS(sched_get_priority_min), QEMU_SECCOMP_SET_RESOURCECTL },
};
diff --git a/vl.c b/vl.c
index 369e3411b1..79ecacdcc6 100644
--- a/vl.c
+++ b/vl.c
@@ -284,6 +284,10 @@ static QemuOptsList qemu_sandbox_opts = {
.name = "spawn",
.type = QEMU_OPT_STRING,
},
+ {
+ .name = "resourcecontrol",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1098,6 +1102,18 @@ static int parse_sandbox(void *opaque, QemuOpts *opts,
Error **errp)
}
}
+ value = qemu_opt_get(opts, "resourcecontrol");
+ if (value) {
+ if (g_str_equal(value, "deny")) {
+ seccomp_opts |= QEMU_SECCOMP_SET_RESOURCECTL;
+ } else if (g_str_equal(value, "allow")) {
+ /* 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");
--
2.13.5
