From: Milan Broz <gmazyland@gmail.com> mainline inclusion from mainline-5.6-rc1 commit 4ea9471fbd1addb25a4d269991dc724e200ca5b5 category: bugfix bugzilla: 31797 CVE: NA ----------------------------------------- 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> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Reviewed-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Reviewed-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/md/dm-crypt.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index e225246..3a0aa8f 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -482,8 +482,14 @@ 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 */ -- 1.8.3