From 46c16855b1bed2704549d834acd2e9812ff3bf1e Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Sun, 10 Nov 2019 14:17:33 +0100 Subject: mkfs.ubifs: fscrypt: bail from encrypt_block if gen_essiv_salt fails What originally cought my attention was that gen_essiv_salt has a size_t return type and error paths that return -1 on failure. Further investigation revealed that the error value is never checked for. The encrypt_block function doesn't use the return value in any way and simply continues onward. Furthermore, the gen_essiv_salt function has an error case that emits an error message but returns success state. This patch modifes gen_essiv_salt to return an error status in all error branches, changes the return type to ssize_t and adds a check to encrypt_block if gen_essiv_salt fails. Signed-off-by: David Oberhollenzer --- ubifs-utils/mkfs.ubifs/crypto.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/ubifs-utils/mkfs.ubifs/crypto.c b/ubifs-utils/mkfs.ubifs/crypto.c index cd68e37..d31bd2a 100644 --- a/ubifs-utils/mkfs.ubifs/crypto.c +++ b/ubifs-utils/mkfs.ubifs/crypto.c @@ -109,7 +109,7 @@ fail: return -1; } -static size_t gen_essiv_salt(const void *iv, size_t iv_len, const void *key, size_t key_len, void *salt) +static ssize_t gen_essiv_salt(const void *iv, size_t iv_len, const void *key, size_t key_len, void *salt) { size_t ret; const EVP_CIPHER *cipher; @@ -127,8 +127,10 @@ static size_t gen_essiv_salt(const void *iv, size_t iv_len, const void *key, siz } ret = do_encrypt(cipher, iv, iv_len, sha256, EVP_MD_size(EVP_sha256()), NULL, 0, salt); - if (ret != iv_len) + if (ret != iv_len) { errmsg("Unable to compute ESSIV salt, return value %zi instead of %zi", ret, iv_len); + return -1; + } free(sha256); @@ -154,7 +156,8 @@ static ssize_t encrypt_block(const void *plaintext, size_t size, if (cipher == EVP_aes_128_cbc()) { tweak = alloca(ivsize); - gen_essiv_salt(&iv, FS_IV_SIZE, key, key_len, tweak); + if (gen_essiv_salt(&iv, FS_IV_SIZE, key, key_len, tweak) < 0) + return -1; } else { tweak = &iv; } -- cgit v1.2.3