pw: do not removed home directories if not owned

When deleting a user, if its home directory does not belong to it, it should
not be removed. This is the promise that the manpage makes, the tool should
ensure that it respects that promise.

Add a regression test about it

PR:		244967
Submitted by:	Eric Hanneken <eric@erichanneken.com>
MFC after:	3 days

1 files changed, 4 insertions, 1 deletions

diff --git a/pw/rm_r.c b/pw/rm_r.c
index 940266d..66298a2 100644
--- a/pw/rm_r.c
+++ b/pw/rm_r.c
@@ -71,5 +71,8 @@ rm_r(int rootfd, const char *path, uid_t uid)
 	closedir(d);
 	if (fstatat(rootfd, path, &st, AT_SYMLINK_NOFOLLOW) != 0)
 		return;
-	unlinkat(rootfd, path, S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0);
+	if (S_ISLNK(st.st_mode))
+		unlinkat(rootfd, path, 0);
+	else if (st.st_uid == uid)
+		unlinkat(rootfd, path, AT_REMOVEDIR);
 }