1 files changed, 7 insertions, 2 deletions

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index bcf13d95f54a..2e66f312e2c4 100644
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -131,8 +131,13 @@ unmap_src:
                 memcpy(walk->dst.virt.addr, walk->page, n);
                 skcipher_unmap_dst(walk);
         } else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
-                if (WARN_ON(err)) {
-                        /* unexpected case; didn't process all bytes */
+                if (err) {
+                        /*
+                         * Didn't process all bytes.  Either the algorithm is
+                         * broken, or this was the last step and it turned out
+                         * the message wasn't evenly divisible into blocks but
+                         * the algorithm requires it.
+                         */
                         err = -EINVAL;
                         goto finish;
                 }