1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 796007a5e0e1..7a7bab8947ae 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -330,15 +330,17 @@ test_block_hash:
                                 return r;
                         }
                 }
-
                 todo = 1 << v->data_dev_block_bits;
-                while (io->iter.bi_size) {
+                do {
                         u8 *page;
+                        unsigned len;
                         struct bio_vec bv = bio_iter_iovec(bio, io->iter);
 
                         page = kmap_atomic(bv.bv_page);
-                        r = crypto_shash_update(desc, page + bv.bv_offset,
-                                                bv.bv_len);
+                        len = bv.bv_len;
+                        if (likely(len >= todo))
+                                len = todo;
+                        r = crypto_shash_update(desc, page + bv.bv_offset, len);
                         kunmap_atomic(page);
 
                         if (r < 0) {
@@ -346,8 +348,9 @@ test_block_hash:
                                 return r;
                         }
 
-                        bio_advance_iter(bio, &io->iter, bv.bv_len);
-                }
+                        bio_advance_iter(bio, &io->iter, len);
+                        todo -= len;
+                } while (todo);
 
                 if (!v->version) {
                         r = crypto_shash_update(desc, v->salt, v->salt_size);