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Commit 0bc12704 authored by Eric Biggers's avatar Eric Biggers Committed by Jaegeuk Kim
Browse files

fscrypt: clean up some BUG_ON()s in block encryption/decryption 



Replace some BUG_ON()s with WARN_ON_ONCE() and returning an error code,
and move the check for len divisible by FS_CRYPTO_BLOCK_SIZE into
fscrypt_crypt_block() so that it's done for both encryption and
decryption, not just encryption.

Reviewed-by: default avatarChandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
parent 8126f71c

fs/crypto/crypto.c

+9 −6
Original line number Diff line number Diff line
@@ -161,7 +161,10 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, 
	struct crypto_skcipher *tfm = ci->ci_ctfm;

	int res = 0;



	BUG_ON(len == 0);

	if (WARN_ON_ONCE(len <= 0))

		return -EINVAL;

	if (WARN_ON_ONCE(len % FS_CRYPTO_BLOCK_SIZE != 0))

		return -EINVAL;



	fscrypt_generate_iv(&iv, lblk_num, ci);
@@ -224,8 +227,6 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, 
	struct page *ciphertext_page = page;

	int err;



	BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0);



	if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) {

		/* with inplace-encryption we just encrypt the page */

		err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num, page,
@@ -237,7 +238,8 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, 
		return ciphertext_page;

	}



	BUG_ON(!PageLocked(page));

	if (WARN_ON_ONCE(!PageLocked(page)))

		return ERR_PTR(-EINVAL);



	/* The encryption operation will require a bounce page. */

	ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags);
@@ -274,8 +276,9 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); 
int fscrypt_decrypt_page(const struct inode *inode, struct page *page,

			unsigned int len, unsigned int offs, u64 lblk_num)

{

	if (!(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES))

		BUG_ON(!PageLocked(page));

	if (WARN_ON_ONCE(!PageLocked(page) &&

			 !(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES)))

		return -EINVAL;



	return fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page, page,

				   len, offs, GFP_NOFS);