static inline int may_create(struct user_namespace *mnt_userns,
struct inode *dir, struct dentry *child)
{
- struct user_namespace *s_user_ns;
audit_inode_child(dir, child, AUDIT_TYPE_CHILD_CREATE);
if (child->d_inode)
return -EEXIST;
if (IS_DEADDIR(dir))
return -ENOENT;
- s_user_ns = dir->i_sb->s_user_ns;
- if (!kuid_has_mapping(s_user_ns, mapped_fsuid(mnt_userns)) ||
- !kgid_has_mapping(s_user_ns, mapped_fsgid(mnt_userns)))
+ if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns))
return -EOVERFLOW;
+
return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
}
const struct path *dir, struct dentry *dentry,
umode_t mode)
{
- struct user_namespace *s_user_ns;
int error = security_path_mknod(dir, dentry, mode, 0);
if (error)
return error;
- s_user_ns = dir->dentry->d_sb->s_user_ns;
- if (!kuid_has_mapping(s_user_ns, mapped_fsuid(mnt_userns)) ||
- !kgid_has_mapping(s_user_ns, mapped_fsgid(mnt_userns)))
+ if (!fsuidgid_has_mapping(dir->dentry->d_sb, mnt_userns))
return -EOVERFLOW;
error = inode_permission(mnt_userns, dir->dentry->d_inode,
return kgid_from_mnt(mnt_userns, current_fsgid());
}
+/**
+ * fsuidgid_has_mapping() - check whether caller's fsuid/fsgid is mapped
+ * @sb: the superblock we want a mapping in
+ * @mnt_userns: user namespace of the relevant mount
+ *
+ * Check whether the caller's fsuid and fsgid have a valid mapping in the
+ * s_user_ns of the superblock @sb. If the caller is on an idmapped mount map
+ * the caller's fsuid and fsgid according to the @mnt_userns first.
+ *
+ * Return: true if fsuid and fsgid is mapped, false if not.
+ */
+static inline bool fsuidgid_has_mapping(struct super_block *sb,
+ struct user_namespace *mnt_userns)
+{
+ struct user_namespace *s_user_ns = sb->s_user_ns;
+
+ return kuid_has_mapping(s_user_ns, mapped_fsuid(mnt_userns)) &&
+ kgid_has_mapping(s_user_ns, mapped_fsgid(mnt_userns));
+}
+
extern struct timespec64 current_time(struct inode *inode);
/*