This patch introduces the argument [,obsolete=allow] 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 <otubo@redhat.com>
---
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
#define QEMU_SECCOMP_SET_DEFAULT (1 << 0)
+#define QEMU_SECCOMP_SET_OBSOLETE (1 << 1)
#include <seccomp.h>
-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
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
- "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n",
+ "-sandbox on[,obsolete=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" \
+ " C library implementations.\n",
QEMU_ARCH_ALL)
STEXI
-@item -sandbox @var{arg}
+@item -sandbox @var{arg}[,obsolete=@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'.
+@table @option
+@item obsolete=@var{string}
+Enable Obsolete system calls
+@end table
ETEXI
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[] = {
{ 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 },
};
-int seccomp_start(void)
+
+int seccomp_start(uint32_t seccomp_opts)
{
int rc = 0;
unsigned int i = 0;
@@ -72,6 +85,14 @@ int seccomp_start(void)
for (i = 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 = {
.name = "enable",
.type = QEMU_OPT_BOOL,
},
+ {
+ .name = "obsolete",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1032,7 +1036,23 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
{
if (qemu_opt_get_bool(opts, "enable", false)) {
#ifdef CONFIG_SECCOMP
- if (seccomp_start() < 0) {
+ uint32_t seccomp_opts = 0x00000;
+ const char *value = NULL;
+
+ value = qemu_opt_get(opts, "obsolete");
+ if (value) {
+ if (strcmp(value, "allow") == 0) {
+ seccomp_opts |= 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;
--
2.13.5
On Fri, Sep 01, 2017 at 12:58:14PM +0200, Eduardo Otubo wrote:
> This patch introduces the argument [,obsolete=allow] 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 <otubo@redhat.com>
> ---
> include/sysemu/seccomp.h | 3 ++-
> qemu-options.hx | 12 ++++++++++--
> qemu-seccomp.c | 23 ++++++++++++++++++++++-
> vl.c | 22 +++++++++++++++++++++-
> 4 files changed, 55 insertions(+), 5 deletions(-)
>
> @@ -72,6 +85,14 @@ int seccomp_start(void)
>
> for (i = 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;
THis can be simplified:
if ((seccomp_opts & QEMU_SECCOMP_SET_OBSOLETE)) {
continue;
}
break;
thus avoiding need to 'goto'
Likewise for all following patches
> default:
> goto add_syscall;
> }
Regards,
Daniel
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On Fri, Sep 01, 2017 at 12:05:41PM +0100, Daniel P. Berrange wrote:
> On Fri, Sep 01, 2017 at 12:58:14PM +0200, Eduardo Otubo wrote:
> > This patch introduces the argument [,obsolete=allow] 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 <otubo@redhat.com>
> > ---
> > include/sysemu/seccomp.h | 3 ++-
> > qemu-options.hx | 12 ++++++++++--
> > qemu-seccomp.c | 23 ++++++++++++++++++++++-
> > vl.c | 22 +++++++++++++++++++++-
> > 4 files changed, 55 insertions(+), 5 deletions(-)
> >
>
> > @@ -72,6 +85,14 @@ int seccomp_start(void)
> >
> > for (i = 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;
>
> THis can be simplified:
>
> if ((seccomp_opts & QEMU_SECCOMP_SET_OBSOLETE)) {
> continue;
> }
>
> break;
>
> thus avoiding need to 'goto'
>
> Likewise for all following patches
Do you think there's anything else to fix on this series? if nothing
else emerges, I'll send the v5 tomorrow (also with the style fixes).
--
Eduardo Otubo
Senior Software Engineer @ RedHat
On Thu, Sep 07, 2017 at 11:31:04AM +0200, Eduardo Otubo wrote:
> On Fri, Sep 01, 2017 at 12:05:41PM +0100, Daniel P. Berrange wrote:
> > On Fri, Sep 01, 2017 at 12:58:14PM +0200, Eduardo Otubo wrote:
> > > This patch introduces the argument [,obsolete=allow] 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 <otubo@redhat.com>
> > > ---
> > > include/sysemu/seccomp.h | 3 ++-
> > > qemu-options.hx | 12 ++++++++++--
> > > qemu-seccomp.c | 23 ++++++++++++++++++++++-
> > > vl.c | 22 +++++++++++++++++++++-
> > > 4 files changed, 55 insertions(+), 5 deletions(-)
> > >
> >
> > > @@ -72,6 +85,14 @@ int seccomp_start(void)
> > >
> > > for (i = 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;
> >
> > THis can be simplified:
> >
> > if ((seccomp_opts & QEMU_SECCOMP_SET_OBSOLETE)) {
> > continue;
> > }
> >
> > break;
> >
> > thus avoiding need to 'goto'
> >
> > Likewise for all following patches
>
> Do you think there's anything else to fix on this series? if nothing
> else emerges, I'll send the v5 tomorrow (also with the style fixes).
I just sent one more comment, but apart from the that & the style fixes
it looks good to me.
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
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On Fri, Sep 01, 2017 at 12:58:14PM +0200, Eduardo Otubo wrote:
> This patch introduces the argument [,obsolete=allow] 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 <otubo@redhat.com>
> ---
> include/sysemu/seccomp.h | 3 ++-
> qemu-options.hx | 12 ++++++++++--
> qemu-seccomp.c | 23 ++++++++++++++++++++++-
> vl.c | 22 +++++++++++++++++++++-
> 4 files changed, 55 insertions(+), 5 deletions(-)
>
> @@ -1032,7 +1036,23 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
> {
> if (qemu_opt_get_bool(opts, "enable", false)) {
> #ifdef CONFIG_SECCOMP
> - if (seccomp_start() < 0) {
> + uint32_t seccomp_opts = 0x00000;
> + const char *value = NULL;
> +
> + value = qemu_opt_get(opts, "obsolete");
> + if (value) {
> + if (strcmp(value, "allow") == 0) {
I would have a slight preference for g_str_equal(value, "allow")
> + seccomp_opts |= QEMU_SECCOMP_SET_OBSOLETE;
> + } else if (strcmp(value, "deny")) {
and !g_str_equal(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");
> + }
There seem to be tabs for indent here too
> + }
> +
> + if (seccomp_start(seccomp_opts) < 0) {
> error_report("failed to install seccomp syscall filter "
> "in the kernel");
> return -1;
> --
> 2.13.5
>
Regards,
Daniel
--
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