| Message ID | 1498481386-8704-1-git-send-email-marmarek@invisiblethingslab.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/26/2017 02:49 PM, Marek Marczykowski-Górecki wrote: > Userspace application can do a hypercall through /dev/xen/privcmd, and > some for some hypercalls argument is a pointers to user-provided > structure. When SMAP is supported and enabled, hypervisor can't access. > So, lets allow it. > > The same applies to HYPERVISOR_dm_op, where additionally privcmd driver > carefully verify buffer addresses. > > Cc: stable@vger.kernel.org > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Juergen Gross <jgross@suse.com> Thanks, Juergen
On 26/06/17 14:49, Marek Marczykowski-Górecki wrote: > Userspace application can do a hypercall through /dev/xen/privcmd, and > some for some hypercalls argument is a pointers to user-provided > structure. When SMAP is supported and enabled, hypervisor can't access. > So, lets allow it. > > The same applies to HYPERVISOR_dm_op, where additionally privcmd driver > carefully verify buffer addresses. > > Cc: stable@vger.kernel.org > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Queued to xen/tip.git for-linus-4.13 Thanks, Juergen
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index f6d20f6..32b74a8 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -43,6 +43,7 @@ #include <asm/page.h> #include <asm/pgtable.h> +#include <asm/smap.h> #include <xen/interface/xen.h> #include <xen/interface/sched.h> @@ -214,10 +215,12 @@ privcmd_call(unsigned call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + stac(); asm volatile("call *%[call]" : __HYPERCALL_5PARAM : [call] "a" (&hypercall_page[call]) : __HYPERCALL_CLOBBER5); + clac(); return (long)__res; } @@ -476,7 +479,11 @@ static inline int HYPERVISOR_dm_op( domid_t dom, unsigned int nr_bufs, void *bufs) { - return _hypercall3(int, dm_op, dom, nr_bufs, bufs); + int ret; + stac(); + ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs); + clac(); + return ret; } static inline void
Userspace application can do a hypercall through /dev/xen/privcmd, and some for some hypercalls argument is a pointers to user-provided structure. When SMAP is supported and enabled, hypervisor can't access. So, lets allow it. The same applies to HYPERVISOR_dm_op, where additionally privcmd driver carefully verify buffer addresses. Cc: stable@vger.kernel.org Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> --- arch/x86/include/asm/xen/hypercall.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) Changes since v1: - add HYPERVISOR_dm_op