From 163be31d380fbdcb56ec06c09e81774840df90dc Mon Sep 17 00:00:00 2001
From: Frantisek Sumsal <frantisek@sumsal.cz>
Date: Thu, 29 Jun 2023 13:31:19 +0200
Subject: [PATCH] core: reorder systemd arguments on reexec

When reexecuting system let's put our arguments carrying deserialization
info first followed by any existing arguments to make sure they get
parsed in case we get weird stuff from the kernel cmdline (like --).

See: https://github.com/systemd/systemd/issues/28184
(cherry picked from commit 06afda6b38d5d730fca3c65449096425933272bc)
(cherry picked from commit 884ab38057dca70b8779c85884f4646057e80921)
---
 src/core/main.c            | 6 +++++-
 test/TEST-01-BASIC/test.sh | 5 +++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/core/main.c b/src/core/main.c
index de6913c912..a84fafa97b 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1815,13 +1815,17 @@ static int do_reexecute(
                 xsprintf(sfd, "--deserialize=%i", fileno(arg_serialization));
 
                 i = 1;         /* Leave args[0] empty for now. */
-                filter_args(args, &i, argv, argc);
 
+                /* Put our stuff first to make sure it always gets parsed in case
+                 * we get weird stuff from the kernel cmdline (like --) */
                 if (switch_root_dir)
                         args[i++] = "--switched-root";
 
                 args[i++] = arg_system ? "--system" : "--user";
                 args[i++] = sfd;
+
+                filter_args(args, &i, argv, argc);
+
                 args[i++] = NULL;
 
                 assert(i <= args_size);
diff --git a/test/TEST-01-BASIC/test.sh b/test/TEST-01-BASIC/test.sh
index cc6d0651c1..d0e714ac30 100755
--- a/test/TEST-01-BASIC/test.sh
+++ b/test/TEST-01-BASIC/test.sh
@@ -8,6 +8,11 @@ RUN_IN_UNPRIVILEGED_CONTAINER=${RUN_IN_UNPRIVILEGED_CONTAINER:-yes}
 TEST_REQUIRE_INSTALL_TESTS=0
 TEST_SUPPORTING_SERVICES_SHOULD_BE_MASKED=0
 
+# Check if we can correctly deserialize if the kernel cmdline contains "weird" stuff
+# like an invalid argument, "end of arguments" separator, or a sysvinit argument (-z)
+# See: https://github.com/systemd/systemd/issues/28184
+KERNEL_APPEND="foo -- -z bar --- baz $KERNEL_APPEND"
+
 # shellcheck source=test/test-functions
 . "${TEST_BASE_DIR:?}/test-functions"