From 687c3c36e754a999a8263745b27965128db4fee5 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 3 Oct 2015 10:49:27 -0400 Subject: [PATCH] ext4 crypto: replace some BUG_ON()'s with error checks Buggy (or hostile) userspace should not be able to cause the kernel to crash. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/crypto.c | 1 - fs/ext4/crypto_fname.c | 2 -- fs/ext4/crypto_key.c | 16 +++++++++++++--- fs/ext4/crypto_policy.c | 3 ++- 4 files changed, 15 insertions(+), 7 deletions(-) diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 3a5a7a2597de..879cb15b7a21 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -295,7 +295,6 @@ static int ext4_page_crypto(struct inode *inode, else res = crypto_ablkcipher_encrypt(req); if (res == -EINPROGRESS || res == -EBUSY) { - BUG_ON(req->base.data != &ecr); wait_for_completion(&ecr.completion); res = ecr.res; } diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c index 847f919c84d9..2fbef8a14760 100644 --- a/fs/ext4/crypto_fname.c +++ b/fs/ext4/crypto_fname.c @@ -120,7 +120,6 @@ static int ext4_fname_encrypt(struct inode *inode, ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv); res = crypto_ablkcipher_encrypt(req); if (res == -EINPROGRESS || res == -EBUSY) { - BUG_ON(req->base.data != &ecr); wait_for_completion(&ecr.completion); res = ecr.res; } @@ -182,7 +181,6 @@ static int ext4_fname_decrypt(struct inode *inode, ablkcipher_request_set_crypt(req, &src_sg, &dst_sg, iname->len, iv); res = crypto_ablkcipher_decrypt(req); if (res == -EINPROGRESS || res == -EBUSY) { - BUG_ON(req->base.data != &ecr); wait_for_completion(&ecr.completion); res = ecr.res; } diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c index 1d510c11b100..f9270ec2a132 100644 --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -71,7 +71,6 @@ static int ext4_derive_key_aes(char deriving_key[EXT4_AES_128_ECB_KEY_SIZE], EXT4_AES_256_XTS_KEY_SIZE, NULL); res = crypto_ablkcipher_encrypt(req); if (res == -EINPROGRESS || res == -EBUSY) { - BUG_ON(req->base.data != &ecr); wait_for_completion(&ecr.completion); res = ecr.res; } @@ -208,7 +207,12 @@ retry: goto out; } crypt_info->ci_keyring_key = keyring_key; - BUG_ON(keyring_key->type != &key_type_logon); + if (keyring_key->type != &key_type_logon) { + printk_once(KERN_WARNING + "ext4: key type must be logon\n"); + res = -ENOKEY; + goto out; + } ukp = ((struct user_key_payload *)keyring_key->payload.data); if (ukp->datalen != sizeof(struct ext4_encryption_key)) { res = -EINVAL; @@ -217,7 +221,13 @@ retry: master_key = (struct ext4_encryption_key *)ukp->data; BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE != EXT4_KEY_DERIVATION_NONCE_SIZE); - BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE); + if (master_key->size != EXT4_AES_256_XTS_KEY_SIZE) { + printk_once(KERN_WARNING + "ext4: key size incorrect: %d\n", + master_key->size); + res = -ENOKEY; + goto out; + } res = ext4_derive_key_aes(ctx.nonce, master_key->raw, raw_key); if (res) diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c index a640ec2c4b13..ad050698143f 100644 --- a/fs/ext4/crypto_policy.c +++ b/fs/ext4/crypto_policy.c @@ -150,7 +150,8 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent, if ((parent == NULL) || (child == NULL)) { pr_err("parent %p child %p\n", parent, child); - BUG_ON(1); + WARN_ON(1); /* Should never happen */ + return 0; } /* no restrictions if the parent directory is not encrypted */ if (!ext4_encrypted_inode(parent)) -- 2.11.0