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| author |   Milan Broz <gmazyland@gmail.com> | 2020-01-06 10:11:47 +0100 |
|---|---|---|
| committer |   Mike Snitzer <snitzer@redhat.com> | 2020-01-14 20:22:47 -0500 |
| commit | 4ea9471fbd1addb25a4d269991dc724e200ca5b5 (patch) | |
| tree | fd553b836f98ce14f66ca7a0b70a75f96f93d067 /drivers/md | |
| parent | dm crypt: Implement Elephant diffuser for Bitlocker compatibility (diff) | |
| download | linux-dev-4ea9471fbd1addb25a4d269991dc724e200ca5b5.tar.xz linux-dev-4ea9471fbd1addb25a4d269991dc724e200ca5b5.zip | |
dm crypt: fix benbi IV constructor crash if used in authenticated mode
If benbi IV is used in AEAD construction, for example:
cryptsetup luksFormat <device> --cipher twofish-xts-benbi --key-size 512 --integrity=hmac-sha256
the constructor uses wrong skcipher function and crashes:
BUG: kernel NULL pointer dereference, address: 00000014
...
EIP: crypt_iv_benbi_ctr+0x15/0x70 [dm_crypt]
Call Trace:
? crypt_subkey_size+0x20/0x20 [dm_crypt]
crypt_ctr+0x567/0xfc0 [dm_crypt]
dm_table_add_target+0x15f/0x340 [dm_mod]
Fix this by properly using crypt_aead_blocksize() in this case.
Fixes: ef43aa38063a6 ("dm crypt: add cryptographic data integrity protection (authenticated encryption)")
Cc: stable@vger.kernel.org # v4.12+
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=941051
Reported-by: Jerad Simpson <jbsimpson@gmail.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-crypt.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 2190f2f55151..c6a529873d0f 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -343,8 +343,14 @@ static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, const char *opts) { - unsigned bs = crypto_skcipher_blocksize(any_tfm(cc)); - int log = ilog2(bs); + unsigned bs; + int log; + + if (test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags)) + bs = crypto_aead_blocksize(any_tfm_aead(cc)); + else + bs = crypto_skcipher_blocksize(any_tfm(cc)); + log = ilog2(bs); /* we need to calculate how far we must shift the sector count * to get the cipher block count, we use this shift in _gen */ |