From f2ae8bfa498831ee6343d672066b898d3cd73892 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@citrix.com>
Date: Tue, 12 Aug 2014 15:38:01 +0200
Subject: [PATCH] xen: arm: Correctly handle do_sysreg exception injection from
 64-bit userspace

The do_sysreg case was missing a return, so it would increment PC and
inject the trap to the second instruction of the handler.

This is CVE-2014-5148 / XSA-103.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Julien Grall <julien.grall@linaro.org>
---
 xen/arch/arm/traps.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index ae594caea7..683b4400f9 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1704,6 +1704,7 @@ static void do_sysreg(struct cpu_user_regs *regs,
                      hsr.bits & HSR_SYSREG_REGS_MASK);
 #endif
             inject_undef_exception(regs, sysreg.len);
+            return;
         }
     }
 
-- 
2.30.2