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author | Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> | 2017-06-26 12:49:46 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-27 22:08:01 (GMT) |
commit | 4d3d3a1690c25205b36f6ec015458466e1ea6dae (patch) | |
tree | a74eef610151f59b6b97a14bf889d3f112f37cdf | |
parent | 03c1d9d45582e8a0991747a6f7a3a235b39b3e2b (diff) | |
download | linux-4d3d3a1690c25205b36f6ec015458466e1ea6dae.tar.xz |
x86/xen: allow userspace access during hypercalls
commit c54590cac51db8ab5fd30156bdaba34af915e629 upstream.
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>
[HYPERVISOR_dm_op dropped - not present until 4.11]
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | arch/x86/include/asm/xen/hypercall.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index a12a047..8b678af 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; } |