dm crypt: reject sector_size feature if device length is not aligned to it

If a crypt mapping uses optional sector_size feature, additional
restrictions to mapped device segment size must be applied in
constructor, otherwise the device activation will fail later.

Fixes: 8f0009a225 ("dm crypt: optionally support larger encryption sector size")
Cc: [e-mail] # 4.12+
Signed-off-by: Milan Broz <[e-mail]>
Signed-off-by: Mike Snitzer <[e-mail]>

drivers/md/dm-crypt.c

···
 				ti->error = "Invalid feature value for sector_size";
 				return -EINVAL;
 			}
+			if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
+				ti->error = "Device size is not multiple of sector_size feature";
+				return -EINVAL;
+			}
 			cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
 		} else if (!strcasecmp(opt_string, "iv_large_sectors"))
 			set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);