diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 62b665cfd2e6..01a19721713b 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -1506,3 +1506,68 @@ struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns, return acl; } EXPORT_SYMBOL_GPL(vfs_get_acl); + +/** + * vfs_remove_acl - remove posix acls + * @mnt_userns: user namespace of the mount + * @dentry: the dentry based on which to retrieve the posix acls + * @acl_name: the name of the posix acl + * + * This function removes posix acls. + * + * Return: On success 0, on error negative errno. + */ +int vfs_remove_acl(struct user_namespace *mnt_userns, struct dentry *dentry, + const char *acl_name) +{ + int acl_type; + int error; + struct inode *inode = d_inode(dentry); + struct inode *delegated_inode = NULL; + + acl_type = posix_acl_type(acl_name); + if (acl_type < 0) + return -EINVAL; + +retry_deleg: + inode_lock(inode); + + /* + * We only care about restrictions the inode struct itself places upon + * us otherwise POSIX ACLs aren't subject to any VFS restrictions. + */ + error = may_write_xattr(mnt_userns, inode); + if (error) + goto out_inode_unlock; + + error = security_inode_remove_acl(mnt_userns, dentry, acl_name); + if (error) + goto out_inode_unlock; + + error = try_break_deleg(inode, &delegated_inode); + if (error) + goto out_inode_unlock; + + if (inode->i_opflags & IOP_XATTR) + error = set_posix_acl(mnt_userns, dentry, acl_type, NULL); + else if (unlikely(is_bad_inode(inode))) + error = -EIO; + else + error = -EOPNOTSUPP; + if (!error) { + fsnotify_xattr(dentry); + evm_inode_post_remove_acl(mnt_userns, dentry, acl_name); + } + +out_inode_unlock: + inode_unlock(inode); + + if (delegated_inode) { + error = break_deleg_wait(&delegated_inode); + if (!error) + goto retry_deleg; + } + + return error; +} +EXPORT_SYMBOL_GPL(vfs_remove_acl); diff --git a/include/linux/evm.h b/include/linux/evm.h index 4a689265958b..045ceee9d649 100644 --- a/include/linux/evm.h +++ b/include/linux/evm.h @@ -36,6 +36,12 @@ extern int evm_inode_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry, const char *xattr_name); extern void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name); +static inline void evm_inode_post_remove_acl(struct user_namespace *mnt_userns, + struct dentry *dentry, + const char *acl_name) +{ + evm_inode_post_removexattr(dentry, acl_name); +} extern int evm_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl); @@ -129,6 +135,13 @@ static inline void evm_inode_post_removexattr(struct dentry *dentry, return; } +static inline void evm_inode_post_remove_acl(struct user_namespace *mnt_userns, + struct dentry *dentry, + const char *acl_name) +{ + return; +} + static inline int evm_inode_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 970567f64a0c..e7995c68f641 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -104,6 +104,8 @@ int vfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl); struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns, struct dentry *dentry, const char *acl_name); +int vfs_remove_acl(struct user_namespace *mnt_userns, struct dentry *dentry, + const char *acl_name); int posix_acl_listxattr(struct inode *inode, char **buffer, ssize_t *remaining_size); #else @@ -147,6 +149,12 @@ static inline struct posix_acl *vfs_get_acl(struct user_namespace *mnt_userns, { return ERR_PTR(-EOPNOTSUPP); } + +static inline int vfs_remove_acl(struct user_namespace *mnt_userns, + struct dentry *dentry, const char *acl_name) +{ + return -EOPNOTSUPP; +} static inline int posix_acl_listxattr(struct inode *inode, char **buffer, ssize_t *remaining_size) {