From: Sunwook Eom <speed....@samsung.com>

commit ad4e80a639fc61d5ecebb03caa5cdbfb91fcebfc upstream.

The error correction data is computed as if data and hash blocks
were concatenated. But hash block number starts from v->hash_start.
So, we have to calculate hash block number based on that.

Fixes: a739ff3f543af ("dm verity: add support for forward error correction")
Cc: sta...@vger.kernel.org
Signed-off-by: Sunwook Eom <speed....@samsung.com>
Reviewed-by: Sami Tolvanen <samitolva...@google.com>
Signed-off-by: Mike Snitzer <snit...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/md/dm-verity-fec.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -447,7 +447,7 @@ int verity_fec_decode(struct dm_verity *
        fio->level++;
 
        if (type == DM_VERITY_BLOCK_TYPE_METADATA)
-               block += v->data_blocks;
+               block = block - v->hash_start + v->data_blocks;
 
        /*
         * For RS(M, N), the continuous FEC data is divided into blocks of N


Reply via email to