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

commit 783874b050768d361239e444ba0fa396bb6d463f upstream.

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")
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index cdf6b1e124604b7bd5e2fee7743a9435f1e79032..cefc27abaad8a7caa9b063ac9263c4f79127e072 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2588,6 +2588,10 @@ static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **ar
                                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);