diff --git a/kernel/fork.c b/kernel/fork.c index c08cf05dd59..208dd99f13b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1606,7 +1606,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL; struct files_struct *fd, *new_fd = NULL; struct sem_undo_list *new_ulist = NULL; - struct nsproxy *new_nsproxy, *old_nsproxy; + struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL; struct uts_namespace *uts, *new_uts = NULL; check_unshare_flags(&unshare_flags); @@ -1634,18 +1634,24 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) if ((err = unshare_utsname(unshare_flags, &new_uts))) goto bad_unshare_cleanup_semundo; - if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist || - new_uts) { - + if (new_ns || new_uts) { old_nsproxy = current->nsproxy; new_nsproxy = dup_namespaces(old_nsproxy); if (!new_nsproxy) { err = -ENOMEM; goto bad_unshare_cleanup_uts; } + } + + if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist || + new_uts) { task_lock(current); - current->nsproxy = new_nsproxy; + + if (new_nsproxy) { + current->nsproxy = new_nsproxy; + new_nsproxy = old_nsproxy; + } if (new_fs) { fs = current->fs; @@ -1687,9 +1693,11 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) } task_unlock(current); - put_nsproxy(old_nsproxy); } + if (new_nsproxy) + put_nsproxy(new_nsproxy); + bad_unshare_cleanup_uts: if (new_uts) put_uts_ns(new_uts);