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Commit 687c3c36 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

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: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
parent 3684de8c

fs/ext4/crypto.c

+0 −1
Original line number Diff line number Diff line
@@ -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;

	}

fs/ext4/crypto_fname.c

+0 −2
Original line number Diff line number Diff line
@@ -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;

	}

fs/ext4/crypto_key.c

+13 −3
Original line number Diff line number Diff line
@@ -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 @@ int _ext4_get_encryption_info(struct inode *inode) 
		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 @@ int _ext4_get_encryption_info(struct inode *inode) 
	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)

fs/ext4/crypto_policy.c

+2 −1
Original line number Diff line number Diff line
@@ -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))