The dm-crypt cipher specification in a mapping table is defined as
  cipher[:keycount]-chainmode-ivmode[:ivopts] or with the new crypt API format
  capi:cipher_api_spec-ivmode[:ivopts].

For ESSIV, the parameter includes hash specification, for example 
aes-cbc-essiv:sha256.

The implementation expected that additional IV option never includes another 
dash '-' character

Unfortunately, with SHA3, we have now names like sha3-256, so the mapping table 
parser fails:

dmsetup create test --table "0 8 crypt aes-cbc-essiv:sha3-256 
9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdb 0"
  or (new format)
dmsetup create test --table "0 8 crypt capi:cbc(aes)-essiv:sha3-256 
9c1185a5c5e9fc54612808977ee8f5b9e 0 /dev/sdb 0"

  device-mapper: crypt: Ignoring unexpected additional cipher options
  device-mapper: table: 253:0: crypt: Error creating IV
  device-mapper: ioctl: error adding target to table

This patch fixes the dm-crypt constructor to ignore additional dash in IV 
options and also removes
bogus warning (that is ignored anyway).

[This patch should go into stable tree as well.]

Signed-off-by: Milan Broz <[email protected]>
---
 drivers/md/dm-crypt.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 0ff22159a0ca..71bfb85f9652 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -2414,9 +2414,21 @@ static int crypt_ctr_cipher_new(struct dm_target *ti, 
char *cipher_in, char *key
         * capi:cipher_api_spec-iv:ivopts
         */
        tmp = &cipher_in[strlen("capi:")];
-       cipher_api = strsep(&tmp, "-");
-       *ivmode = strsep(&tmp, ":");
-       *ivopts = tmp;
+
+       /* Separate IV options if present, it can contain another '-' in hash 
name */
+       *ivopts = strrchr(tmp, ':');
+       if (*ivopts) {
+               **ivopts = '\0';
+               (*ivopts)++;
+       }
+       /* Parse IV mode */
+       *ivmode = strrchr(tmp, '-');
+       if (*ivmode) {
+               **ivmode = '\0';
+               (*ivmode)++;
+       }
+       /* The rest is crypto API spec */
+       cipher_api = tmp;
 
        if (*ivmode && !strcmp(*ivmode, "lmk"))
                cc->tfms_count = 64;
@@ -2486,11 +2498,8 @@ static int crypt_ctr_cipher_old(struct dm_target *ti, 
char *cipher_in, char *key
                goto bad_mem;
 
        chainmode = strsep(&tmp, "-");
-       *ivopts = strsep(&tmp, "-");
-       *ivmode = strsep(&*ivopts, ":");
-
-       if (tmp)
-               DMWARN("Ignoring unexpected additional cipher options");
+       *ivmode   = strsep(&tmp, ":");
+       *ivopts = tmp;
 
        /*
         * For compatibility with the original dm-crypt mapping format, if
-- 
2.20.1

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