diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index ae71e0621317..86c9dd4b334b 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -9,6 +9,16 @@
 #include "xdr.h"
 #include "auth.h"
 
+/*
+ * Sun convention: a sattr time-useconds field of one full second (an
+ * otherwise out-of-range value) means "set this time to the current
+ * server time." It's needed to make permissions checks for the "touch"
+ * program across NFSv2 mounts work correctly. See description of
+ * sattr in section 6.1 of "NFS Illustrated" by Brent Callaghan,
+ * Addison-Wesley, ISBN 0-201-32750-5
+ */
+#define NFS2_SATTR_SET_TO_SERVER_TIME	(1000000)
+
 /*
  * Mapping of S_IF* types to NFS file types
  */
@@ -172,27 +182,29 @@ svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 	tmp1 = be32_to_cpup(p++);
 	tmp2 = be32_to_cpup(p++);
 	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
+		/*
+		 * Range test here to prevent the multiplication from
+		 * wrapping to a valid (but incorrect) value on 32-bit
+		 * platforms.
+		 */
+		if (tmp2 > NFS2_SATTR_SET_TO_SERVER_TIME)
+			return false;
 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 		iap->ia_atime.tv_sec = tmp1;
 		iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
+		if (tmp2 == NFS2_SATTR_SET_TO_SERVER_TIME)
+			iap->ia_valid &= ~ATTR_ATIME_SET;
 	}
 
 	tmp1 = be32_to_cpup(p++);
 	tmp2 = be32_to_cpup(p++);
 	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
+		if (tmp2 > NFS2_SATTR_SET_TO_SERVER_TIME)
+			return false;
 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 		iap->ia_mtime.tv_sec = tmp1;
 		iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
-		/*
-		 * Passing the invalid value useconds=1000000 for mtime
-		 * is a Sun convention for "set both mtime and atime to
-		 * current server time".  It's needed to make permissions
-		 * checks for the "touch" program across v2 mounts to
-		 * Solaris and Irix boxes work correctly. See description of
-		 * sattr in section 6.1 of "NFS Illustrated" by
-		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
-		 */
-		if (tmp2 == 1000000)
+		if (tmp2 == NFS2_SATTR_SET_TO_SERVER_TIME)
 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 	}