diff options
| -rw-r--r-- | Documentation/filesystems/fscrypt.rst | 4 | ||||
| -rw-r--r-- | fs/crypto/hooks.c | 28 | ||||
| -rw-r--r-- | fs/crypto/policy.c | 7 | ||||
| -rw-r--r-- | fs/inode.c | 3 | ||||
| -rw-r--r-- | include/linux/fscrypt.h | 9 |
5 files changed, 49 insertions, 2 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 9c53336d06a4..380a1be9550e 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -513,7 +513,9 @@ FS_IOC_SET_ENCRYPTION_POLICY can fail with the following errors: - ``EEXIST``: the file is already encrypted with an encryption policy different from the one specified - ``EINVAL``: an invalid encryption policy was specified (invalid - version, mode(s), or flags; or reserved bits were set) + version, mode(s), or flags; or reserved bits were set); or a v1 + encryption policy was specified but the directory has the casefold + flag enabled (casefolding is incompatible with v1 policies). - ``ENOKEY``: a v2 encryption policy was specified, but the key with the specified ``master_key_identifier`` has not been added, nor does the process have the CAP_FOWNER capability in the initial user diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index 4081aae4bc35..fd4e5ae21077 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -122,6 +122,34 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, } EXPORT_SYMBOL_GPL(__fscrypt_prepare_lookup); +/** + * fscrypt_prepare_setflags() - prepare to change flags with FS_IOC_SETFLAGS + * @inode: the inode on which flags are being changed + * @oldflags: the old flags + * @flags: the new flags + * + * The caller should be holding i_rwsem for write. + * + * Return: 0 on success; -errno if the flags change isn't allowed or if + * another error occurs. + */ +int fscrypt_prepare_setflags(struct inode *inode, + unsigned int oldflags, unsigned int flags) +{ + struct fscrypt_info *ci; + int err; + + if (IS_ENCRYPTED(inode) && (flags & ~oldflags & FS_CASEFOLD_FL)) { + err = fscrypt_require_key(inode); + if (err) + return err; + ci = inode->i_crypt_info; + if (ci->ci_policy.version != FSCRYPT_POLICY_V2) + return -EINVAL; + } + return 0; +} + int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, unsigned int max_len, struct fscrypt_str *disk_link) diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index f1cff83c151a..cf2a9d26ef7d 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -124,6 +124,13 @@ static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy, policy->filenames_encryption_mode)) return false; + if (IS_CASEFOLDED(inode)) { + /* With v1, there's no way to derive dirhash keys. */ + fscrypt_warn(inode, + "v1 policies can't be used on casefolded directories"); + return false; + } + return true; } diff --git a/fs/inode.c b/fs/inode.c index 96d62d97694e..ea15c6d9f274 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -12,6 +12,7 @@ #include <linux/security.h> #include <linux/cdev.h> #include <linux/memblock.h> +#include <linux/fscrypt.h> #include <linux/fsnotify.h> #include <linux/mount.h> #include <linux/posix_acl.h> @@ -2252,7 +2253,7 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, !capable(CAP_LINUX_IMMUTABLE)) return -EPERM; - return 0; + return fscrypt_prepare_setflags(inode, oldflags, flags); } EXPORT_SYMBOL(vfs_ioc_setflags_prepare); diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 6fe8d0f96a4a..3984eadd7023 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -263,6 +263,8 @@ extern int __fscrypt_prepare_rename(struct inode *old_dir, unsigned int flags); extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, struct fscrypt_name *fname); +extern int fscrypt_prepare_setflags(struct inode *inode, + unsigned int oldflags, unsigned int flags); extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, unsigned int max_len, struct fscrypt_str *disk_link); @@ -519,6 +521,13 @@ static inline int __fscrypt_prepare_lookup(struct inode *dir, return -EOPNOTSUPP; } +static inline int fscrypt_prepare_setflags(struct inode *inode, + unsigned int oldflags, + unsigned int flags) +{ + return 0; +} + static inline int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, unsigned int max_len, |