From: Milan Broz <gmazyland@gmail.com>
Date: Wed, 13 Sep 2017 13:45:56 +0000 (+0200)
Subject: dm crypt: reject sector_size feature if device length is not aligned to it
X-Git-Tag: v4.13.6~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a986ac2486ffcbd577e37b1220237e1fc414672;p=thirdparty%2Fkernel%2Fstable.git

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 cdf6b1e124604..cefc27abaad8a 100644
--- 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);