On 4/4/19 11:12 AM, Dan Carpenter wrote:
The "call" variable comes from the user in privcmd_ioctl_hypercall(). It's an offset into the hypercall_page[] which has (PAGE_SIZE / 32) elements. We need to put an upper bound on it to prevent an out of bounds access.
Fixes: 1246ae0bb992 ("xen: add variable hypercall caller") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com
Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com
I am also adding stable@vger.kernel.org
-boris
arch/x86/include/asm/xen/hypercall.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index de6f0d59a24f..2863c2026655 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -206,6 +206,9 @@ xen_single_call(unsigned int call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
- if (call >= PAGE_SIZE / sizeof(hypercall_page[0]))
return -EINVAL;- asm volatile(CALL_NOSPEC : __HYPERCALL_5PARAM : [thunk_target] "a" (&hypercall_page[call])