crypto: validate that LUKS payload doesn't overlap with header

We already validate that LUKS keyslots don't overlap with the
header, or with each other. This closes the remaining hole in
validation of LUKS file regions.

Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 6ef9a89ffa96ab792c1936195fdfe2de6fe9996c..f22bc63e5460c7001590a336f0408fa6fcfa9eab 100644 (file)
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -572,6 +572,13 @@ qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp)
         return -1;
     }
 
+    if (luks->header.payload_offset_sector <
+        DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET,
+                     QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) {
+        error_setg(errp, "LUKS payload is overlapping with the header");
+        return -1;
+    }
+
     /* Check all keyslots for corruption  */
     for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; i++) {