From: Eric Biggers <[email protected]> Filesystems don't need fscrypt_fname_encrypted_size() anymore, so unexport it and move it to fscrypt_private.h.
We also never calculate the encrypted size of a filename without having the fscrypt_info present since it is needed to know the amount of NUL-padding which is determined by the encryption policy, and also we will always truncate the NUL-padding to the maximum filename length. Therefore, also make fscrypt_fname_encrypted_size() assume that the fscrypt_info is present, and make it truncate the returned length to the specified max_len. Signed-off-by: Eric Biggers <[email protected]> --- fs/crypto/fname.c | 31 +++++++++++++++---------------- fs/crypto/fscrypt_private.h | 3 +++ fs/crypto/hooks.c | 10 +++++----- include/linux/fscrypt_notsupp.h | 8 -------- include/linux/fscrypt_supp.h | 1 - 5 files changed, 23 insertions(+), 30 deletions(-) diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 44ddd094b7c5..e33f3d3c5ade 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -191,17 +191,20 @@ static int digest_decode(const char *src, int len, char *dst) return cp - dst; } -u32 fscrypt_fname_encrypted_size(const struct inode *inode, u32 ilen) +bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len, + u32 max_len, u32 *encrypted_len_ret) { - int padding = 32; - struct fscrypt_info *ci = inode->i_crypt_info; - - if (ci) - padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK); - ilen = max(ilen, (u32)FS_CRYPTO_BLOCK_SIZE); - return round_up(ilen, padding); + int padding = 4 << (inode->i_crypt_info->ci_flags & + FS_POLICY_FLAGS_PAD_MASK); + u32 encrypted_len; + + if (orig_len > max_len) + return false; + encrypted_len = max(orig_len, (u32)FS_CRYPTO_BLOCK_SIZE); + encrypted_len = round_up(encrypted_len, padding); + *encrypted_len_ret = min(encrypted_len, max_len); + return true; } -EXPORT_SYMBOL(fscrypt_fname_encrypted_size); /** * fscrypt_fname_alloc_buffer - allocate a buffer for presented filenames @@ -342,14 +345,10 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, return ret; if (dir->i_crypt_info) { - unsigned int max_len = dir->i_sb->s_cop->max_namelen(dir); - - if (iname->len > max_len) + if (!fscrypt_fname_encrypted_size(dir, iname->len, + dir->i_sb->s_cop->max_namelen(dir), + &fname->crypto_buf.len)) return -ENAMETOOLONG; - - fname->crypto_buf.len = - min(fscrypt_fname_encrypted_size(dir, iname->len), - max_len); fname->crypto_buf.name = kmalloc(fname->crypto_buf.len, GFP_NOFS); if (!fname->crypto_buf.name) diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 053917587200..ad6722bae8b7 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -110,6 +110,9 @@ extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx, /* fname.c */ extern int fname_encrypt(struct inode *inode, const struct qstr *iname, u8 *out, unsigned int olen); +extern bool fscrypt_fname_encrypted_size(const struct inode *inode, + u32 orig_len, u32 max_len, + u32 *encrypted_len_ret); /* keyinfo.c */ extern void __exit fscrypt_essiv_cleanup(void); diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index ff20cacdea94..3e84d92215a1 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -139,12 +139,12 @@ int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, * counting it (even though it is meaningless for ciphertext) is simpler * for now since filesystems will assume it is there and subtract it. */ - if (sizeof(struct fscrypt_symlink_data) + len > max_len) + if (!fscrypt_fname_encrypted_size(dir, len, + max_len - sizeof(struct fscrypt_symlink_data), + &disk_link->len)) return -ENAMETOOLONG; - disk_link->len = min_t(unsigned int, - sizeof(struct fscrypt_symlink_data) + - fscrypt_fname_encrypted_size(dir, len), - max_len); + disk_link->len += sizeof(struct fscrypt_symlink_data); + disk_link->name = NULL; return 0; } diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h index c9592e307df5..342eb97e0476 100644 --- a/include/linux/fscrypt_notsupp.h +++ b/include/linux/fscrypt_notsupp.h @@ -131,14 +131,6 @@ static inline void fscrypt_free_filename(struct fscrypt_name *fname) return; } -static inline u32 fscrypt_fname_encrypted_size(const struct inode *inode, - u32 ilen) -{ - /* never happens */ - WARN_ON(1); - return 0; -} - static inline int fscrypt_fname_alloc_buffer(const struct inode *inode, u32 max_encrypted_len, struct fscrypt_str *crypto_str) diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h index e00191deb0d6..2dd5767c77b0 100644 --- a/include/linux/fscrypt_supp.h +++ b/include/linux/fscrypt_supp.h @@ -107,7 +107,6 @@ static inline void fscrypt_free_filename(struct fscrypt_name *fname) kfree(fname->crypto_buf.name); } -extern u32 fscrypt_fname_encrypted_size(const struct inode *, u32); extern int fscrypt_fname_alloc_buffer(const struct inode *, u32, struct fscrypt_str *); extern void fscrypt_fname_free_buffer(struct fscrypt_str *); -- 2.15.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
