2 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index c991b3a7b904..0f1cf5d53dd8 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -127,6 +127,15 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
 {
         int err;
 
+        /*
+         * Clear the bytes not touched by the fxsave and reserved
+         * for the SW usage.
+         */
+        err = __clear_user(&fx->sw_reserved,
+                           sizeof(struct _fpx_sw_bytes));
+        if (unlikely(err))
+                return -EFAULT;
+
         asm volatile("1:  rex64/fxsave (%[fx])\n\t"
                      "2:\n"
                      ".section .fixup,\"ax\"\n"
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 2c4390cae228..30dfc81804d5 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -59,6 +59,16 @@ static inline int fpu_xrstor_checking(struct fpu *fpu)
 static inline int xsave_user(struct xsave_struct __user *buf)
 {
         int err;
+
+        /*
+         * Clear the xsave header first, so that reserved fields are
+         * initialized to zero.
+         */
+        err = __clear_user(&buf->xsave_hdr,
+                           sizeof(struct xsave_hdr_struct));
+        if (unlikely(err))
+                return -EFAULT;
+
         __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
                              "2:\n"
                              ".section .fixup,\"ax\"\n"