diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index bed6215..41e3b6a 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -6,7 +6,10 @@
 Samba supports newer POSIX CIFS Protocol Extensions). Add "nounix"
 mount option to allow disabling the CIFS Unix Extensions for just
 that mount. Fix hang on spinlock in find_writable_file (race when
-reopening file after session crash).
+reopening file after session crash).  Byte range unlock request to
+windows server could unlock more bytes (on server copy of file)
+than intended if start of unlock request is well before start of
+a previous byte range lock that we issued.
 
 Version 1.49
 ------------
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 894b1f7..f9bd8b8 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -767,7 +767,8 @@
 			mutex_lock(&fid->lock_mutex);
 			list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
 				if (pfLock->fl_start <= li->offset &&
-						length >= li->length) {
+						(pflock->fl_start + length) >=
+						(li->offset + li->length)) {
 					stored_rc = CIFSSMBLock(xid, pTcon,
 							netfid,
 							li->length, li->offset,