The code still wipes key material with memset(). Use memzero_explicit() to prevent the compiler from optimizing these wipes away.
Also use size_t for the string length passed to memzero_explicit() and drop the redundant sizeof(u8) multiplications. Signed-off-by: Thorsten Blum <[email protected]> --- drivers/md/dm-crypt.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 608b617fb817..5194294871db 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -513,7 +513,7 @@ static void crypt_iv_lmk_wipe(struct crypt_config *cc) struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; if (lmk->seed) - memset(lmk->seed, 0, LMK_SEED_SIZE); + memzero_explicit(lmk->seed, LMK_SEED_SIZE); } static void crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, @@ -630,8 +630,8 @@ static void crypt_iv_tcw_wipe(struct crypt_config *cc) { struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; - memset(tcw->iv_seed, 0, cc->iv_size); - memset(tcw->whitening, 0, TCW_WHITENING_SIZE); + memzero_explicit(tcw->iv_seed, cc->iv_size); + memzero_explicit(tcw->whitening, TCW_WHITENING_SIZE); } static void crypt_iv_tcw_whitening(struct crypt_config *cc, @@ -2596,7 +2596,7 @@ static int get_key_size(char **key_string) static int crypt_set_key(struct crypt_config *cc, char *key) { int r = -EINVAL; - int key_string_len = strlen(key); + size_t key_string_len = strlen(key); /* Hyphen (which gives a key_size of zero) means there is no key. */ if (!cc->key_size && strcmp(key, "-")) @@ -2625,7 +2625,7 @@ static int crypt_set_key(struct crypt_config *cc, char *key) out: /* Hex key string not needed after here, so wipe it. */ - memset(key, '0', key_string_len); + memzero_explicit(key, key_string_len); return r; } @@ -2644,7 +2644,7 @@ static int crypt_wipe_key(struct crypt_config *cc) kfree_sensitive(cc->key_string); cc->key_string = NULL; r = crypt_setkey(cc); - memset(&cc->key, 0, cc->key_size * sizeof(u8)); + memzero_explicit(cc->key, cc->key_size); return r; } @@ -3065,7 +3065,7 @@ static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) /* wipe the kernel key payload copy */ if (cc->key_string) - memset(cc->key, 0, cc->key_size * sizeof(u8)); + memzero_explicit(cc->key, cc->key_size); return ret; } @@ -3644,7 +3644,7 @@ static int crypt_message(struct dm_target *ti, unsigned int argc, char **argv, /* The key size may not be changed. */ key_size = get_key_size(&argv[2]); if (key_size < 0 || cc->key_size != key_size) { - memset(argv[2], '0', strlen(argv[2])); + memzero_explicit(argv[2], strlen(argv[2])); return -EINVAL; } @@ -3655,7 +3655,7 @@ static int crypt_message(struct dm_target *ti, unsigned int argc, char **argv, ret = cc->iv_gen_ops->init(cc); /* wipe the kernel key payload copy */ if (cc->key_string) - memset(cc->key, 0, cc->key_size * sizeof(u8)); + memzero_explicit(cc->key, cc->key_size); return ret; } if (argc == 2 && !strcasecmp(argv[1], "wipe"))
