From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Tue, 23 Apr 2024 08:19:38 +0000 (+0200)
Subject: Avoid TOCTOU issue in start_journal_remote()
X-Git-Tag: v23.1~98
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8cbde8a4ed20a078ad5c70fe38c0dd2294a68bb1;p=thirdparty%2Fmkosi.git

Avoid TOCTOU issue in start_journal_remote()
---

diff --git a/mkosi/qemu.py b/mkosi/qemu.py
index f663917b8..516f21bc0 100644
--- a/mkosi/qemu.py
+++ b/mkosi/qemu.py
@@ -426,7 +426,9 @@ def start_journal_remote(config: Config, sockfd: int) -> Iterator[None]:
 
     d = config.forward_journal.parent if config.forward_journal.suffix == ".journal" else config.forward_journal
     if not d.exists():
-        d.mkdir(parents=True)
+        # Pass exist_ok=True because multiple mkosi processes might be trying to create the parent directory at the
+        # same time.
+        d.mkdir(exist_ok=True, parents=True)
         # Make sure COW is disabled so systemd-journal-remote doesn't complain on btrfs filesystems.
         run(["chattr", "+C", d], check=False, stderr=subprocess.DEVNULL if not ARG_DEBUG.get() else None)
         INVOKING_USER.chown(d)