udf: prevent speculative execution

CVE-2017-5753
CVE-2017-5715

Real commit text tbd
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
(cherry picked from commit b1ff40b60f2b6c5e731b338d429fb06ef7087ace)
Signed-off-by: Andy Whitcroft <apw@canonical.com>

fs/udf/misc.c

@@ -104,6 +104,8 @@ struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
 					iinfo->i_lenEAttr) {
 				uint32_t aal =
 					le32_to_cpu(eahd->appAttrLocation);
+
+				gmb();
 				memmove(&ea[offset - aal + size],
 					&ea[aal], offset - aal);
 				offset -= aal;
@@ -114,6 +116,8 @@ struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
 					iinfo->i_lenEAttr) {
 				uint32_t ial =
 					le32_to_cpu(eahd->impAttrLocation);
+
+				gmb();
 				memmove(&ea[offset - ial + size],
 					&ea[ial], offset - ial);
 				offset -= ial;
@@ -125,6 +129,8 @@ struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
 					iinfo->i_lenEAttr) {
 				uint32_t aal =
 					le32_to_cpu(eahd->appAttrLocation);
+
+				gmb();
 				memmove(&ea[offset - aal + size],
 					&ea[aal], offset - aal);
 				offset -= aal;