From 6f8ef80bb3ba5d244a428aee200c168e809a0079 Mon Sep 17 00:00:00 2001

From: Mike Yuan <me@yhndnzj.com>

Date: Sun, 26 May 2024 00:53:46 +0800

Subject: [PATCH 2/2] core/dbus-execute: don't trigger assertion if

 WorkingDirectory="" or "-"

Follow-up for 14631951cea807de2d482a430841c604c2040718

Before this commit, if WorkingDirectory= is empty or literally "-",

'simplified' is not populated, resulting in the ASSERT_PTR

in unit_write_settingf() below getting triggered.

Also, do not accept "-", so that the parser is consistent

with load-fragment.c

Fixes #33015

---

 src/core/dbus-execute.c | 49 ++++++++++++++++++++++-------------------

 1 file changed, 26 insertions(+), 23 deletions(-)

diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c

index e55fb6ee16..21c260b26b 100644

--- a/src/core/dbus-execute.c

+++ b/src/core/dbus-execute.c

@@ -2716,38 +2716,38 @@ int bus_exec_context_set_transient_property(

         } else if (streq(name, "WorkingDirectory")) {

                 _cleanup_free_ char *simplified = NULL;

-                bool missing_ok, is_home;

+                bool missing_ok = false, is_home = false;

                 const char *s;

                 r = sd_bus_message_read(message, "s", &s);

                 if (r < 0)

                         return r;

-                if (s[0] == '-') {

-                        missing_ok = true;

-                        s++;

-                } else

-                        missing_ok = false;

-

-                if (isempty(s))

-                        is_home = false;

-                else if (streq(s, "~"))

-                        is_home = true;

-                else {

-                        if (!path_is_absolute(s))

-                                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "WorkingDirectory= expects an absolute path or '~'");

+                if (!isempty(s)) {

+                        if (s[0] == '-') {

+                                missing_ok = true;

+                                s++;

+                        }

-                        r = path_simplify_alloc(s, &simplified);

-                        if (r < 0)

-                                return r;

+                        if (streq(s, "~"))

+                                is_home = true;

+                        else {

+                                if (!path_is_absolute(s))

+                                        return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS,

+                                                                "WorkingDirectory= expects an absolute path or '~'");

-                        if (!path_is_normalized(simplified))

-                                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "WorkingDirectory= expects a normalized path or '~'");

+                                r = path_simplify_alloc(s, &simplified);

+                                if (r < 0)

+                                        return r;

-                        if (path_below_api_vfs(simplified))

-                                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "WorkingDirectory= may not be below /proc/, /sys/ or /dev/.");

+                                if (!path_is_normalized(simplified))

+                                        return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS,

+                                                                "WorkingDirectory= expects a normalized path or '~'");

-                        is_home = false;

+                                if (path_below_api_vfs(simplified))

+                                        return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS,

+                                                                "WorkingDirectory= may not be below /proc/, /sys/ or /dev/");

+                        }

                 }

                 if (!UNIT_WRITE_FLAGS_NOOP(flags)) {

@@ -2755,7 +2755,10 @@ int bus_exec_context_set_transient_property(

                         c->working_directory_home = is_home;

                         c->working_directory_missing_ok = missing_ok;

-                        unit_write_settingf(u, flags|UNIT_ESCAPE_SPECIFIERS, name, "WorkingDirectory=%s%s", missing_ok ? "-" : "", c->working_directory_home ? "~" : ASSERT_PTR(c->working_directory));

+                        unit_write_settingf(u, flags|UNIT_ESCAPE_SPECIFIERS, name,

+                                            "WorkingDirectory=%s%s",

+                                            c->working_directory_missing_ok ? "-" : "",

+                                            c->working_directory_home ? "~" : strempty(c->working_directory));

                 }

                 return 1;

-- 

2.45.1