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Blame SOURCES/0727-core-be-stricter-when-handling-PID-files-and-MAINPID.patch

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From c0f32feb77768aa76d8c813471b3484c93bc2651 Mon Sep 17 00:00:00 2001
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From: Lennart Poettering <lennart@poettering.net>
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Date: Fri, 5 Jan 2018 12:20:22 +0100
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Subject: [PATCH] core: be stricter when handling PID files and MAINPID
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 sd_notify() messages
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Let's be more restrictive when validating PID files and MAINPID=
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messages: don't accept PIDs that make no sense, and if the configuration
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source is not trusted, don't accept out-of-cgroup PIDs. A configuratin
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source is considered trusted when the PID file is owned by root, or the
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message was received from root.
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This should lock things down a bit, in case service authors write out
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PID files from unprivileged code or use NotifyAccess=all with
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unprivileged code. Note that doing so was always problematic, just now
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it's a bit less problematic.
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When we open the PID file we'll now use the CHASE_SAFE chase_symlinks()
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logic, to ensure that we won't follow an unpriviled-owned symlink to a
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privileged-owned file thinking this was a valid privileged PID file,
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even though it really isn't.
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Fixes: #6632
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(cherry picked from commit db256aab13d8a89d583ecd2bacf0aca87c66effc)
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Resolves: #1663143
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---
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 man/systemd.service.xml                |  18 ++-
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 src/core/manager.c                     |  17 ++-
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 src/core/service.c                     | 166 ++++++++++++++++------
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 src/core/unit.h                        |   2 +-
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 test/TEST-20-MAINPIDGAMES/Makefile     |   1 +
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 test/TEST-20-MAINPIDGAMES/test.sh      |  81 +++++++++++
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 test/TEST-20-MAINPIDGAMES/testsuite.sh | 189 +++++++++++++++++++++++++
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 test/test-functions                    |   2 +-
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 8 files changed, 418 insertions(+), 58 deletions(-)
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 create mode 120000 test/TEST-20-MAINPIDGAMES/Makefile
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 create mode 100755 test/TEST-20-MAINPIDGAMES/test.sh
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 create mode 100755 test/TEST-20-MAINPIDGAMES/testsuite.sh
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diff --git a/man/systemd.service.xml b/man/systemd.service.xml
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index d147e449a6..565a783f72 100644
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--- a/man/systemd.service.xml
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+++ b/man/systemd.service.xml
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@@ -221,16 +221,14 @@
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       <varlistentry>
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         <term><varname>PIDFile=</varname></term>
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-        <listitem><para>Takes an absolute file name pointing to the
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-        PID file of this daemon. Use of this option is recommended for
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-        services where <varname>Type=</varname> is set to
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-        <option>forking</option>. systemd will read the PID of the
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-        main process of the daemon after start-up of the service.
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-        systemd will not write to the file configured here, although
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-        it will remove the file after the service has shut down if it
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-        still exists.
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-        </para>
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-        </listitem>
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+        <listitem><para>Takes an absolute path referring to the PID file of the service. Usage of this option is
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+        recommended for services where <varname>Type=</varname> is set to <option>forking</option>. The service manager
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+        will read the PID of the main process of the service from this file after start-up of the service. The service
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+        manager will not write to the file configured here, although it will remove the file after the service has shut
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+        down if it still exists. The PID file does not need to be owned by a privileged user, but if it is owned by an
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+        unprivileged user additional safety restrictions are enforced: the file may not be a symlink to a file owned by
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+        a different user (neither directly nor indirectly), and the PID file must refer to a process already belonging
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+        to the service.</para></listitem>
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       </varlistentry>
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       <varlistentry>
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diff --git a/src/core/manager.c b/src/core/manager.c
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index 73d6c81fdb..3bca61d0b1 100644
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--- a/src/core/manager.c
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+++ b/src/core/manager.c
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@@ -1658,11 +1658,18 @@ static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, ui
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         return 0;
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 }
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-static void manager_invoke_notify_message(Manager *m, Unit *u, pid_t pid, const char *buf, FDSet *fds) {
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+static void manager_invoke_notify_message(
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+                Manager *m,
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+                Unit *u,
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+                const struct ucred *ucred,
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+                const char *buf,
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+                FDSet *fds) {
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+
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         _cleanup_strv_free_ char **tags = NULL;
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         assert(m);
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         assert(u);
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+        assert(ucred);
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         assert(buf);
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         tags = strv_split(buf, "\n\r");
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@@ -1674,7 +1681,7 @@ static void manager_invoke_notify_message(Manager *m, Unit *u, pid_t pid, const
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         log_unit_debug(u->id, "Got notification message for unit %s", u->id);
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         if (UNIT_VTABLE(u)->notify_message)
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-                UNIT_VTABLE(u)->notify_message(u, pid, tags, fds);
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+                UNIT_VTABLE(u)->notify_message(u, ucred, tags, fds);
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         else if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
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                 _cleanup_free_ char *x = NULL, *y = NULL;
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@@ -1777,19 +1784,19 @@ static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t
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          * to avoid notifying the same one multiple times. */
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         u1 = manager_get_unit_by_pid(m, ucred->pid);
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         if (u1) {
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-                manager_invoke_notify_message(m, u1, ucred->pid, buf, fds);
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+                manager_invoke_notify_message(m, u1, ucred, buf, fds);
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                 found = true;
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         }
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         u2 = hashmap_get(m->watch_pids1, LONG_TO_PTR(ucred->pid));
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         if (u2 && u2 != u1) {
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-                manager_invoke_notify_message(m, u2, ucred->pid, buf, fds);
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+                manager_invoke_notify_message(m, u2, ucred, buf, fds);
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                 found = true;
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         }
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         u3 = hashmap_get(m->watch_pids2, LONG_TO_PTR(ucred->pid));
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         if (u3 && u3 != u2 && u3 != u1) {
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-                manager_invoke_notify_message(m, u3, ucred->pid, buf, fds);
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+                manager_invoke_notify_message(m, u3, ucred, buf, fds);
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                 found = true;
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         }
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diff --git a/src/core/service.c b/src/core/service.c
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index fe6e2ff17c..06b39e3a5a 100644
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--- a/src/core/service.c
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+++ b/src/core/service.c
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@@ -700,9 +700,45 @@ static void service_dump(Unit *u, FILE *f, const char *prefix) {
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         }
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 }
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+static int service_is_suitable_main_pid(Service *s, pid_t pid, int prio) {
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+        Unit *owner;
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+
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+        assert(s);
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+        assert(pid > 0);
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+
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+        /* Checks whether the specified PID is suitable as main PID for this service. returns negative if not, 0 if the
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+         * PID is questionnable but should be accepted if the source of configuration is trusted. > 0 if the PID is
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+         * good */
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+
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+        if (pid == getpid() || pid == 1) {
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+                log_unit_full(UNIT(s)->id, prio, "New main PID "PID_FMT" is the manager, refusing.", pid);
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+                return -EPERM;
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+        }
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+
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+        if (pid == s->control_pid) {
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+                log_unit_full(UNIT(s)->id, prio, "New main PID "PID_FMT" is the control process, refusing.", pid);
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+                return -EPERM;
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+        }
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+
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+        if (!pid_is_alive(pid)) {
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+                log_unit_full(UNIT(s)->id, prio, "New main PID "PID_FMT" does not exist or is a zombie.", pid);
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+                return -ESRCH;
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+        }
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+
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+        owner = manager_get_unit_by_pid(UNIT(s)->manager, pid);
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+        if (owner == UNIT(s)) {
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+                log_unit_debug(UNIT(s)->id, "New main PID "PID_FMT" belongs to service, we are happy.", pid);
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+                return 1; /* Yay, it's definitely a good PID */
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+        }
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+
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+        return 0; /* Hmm it's a suspicious PID, let's accept it if configuration source is trusted */
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+}
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+
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 static int service_load_pid_file(Service *s, bool may_warn) {
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+        char procfs[sizeof("/proc/self/fd/") - 1 + DECIMAL_STR_MAX(int)];
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         _cleanup_free_ char *k = NULL;
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-        int r;
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+        _cleanup_close_ int fd = -1;
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+        int r, prio;
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         pid_t pid;
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         assert(s);
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@@ -710,30 +746,47 @@ static int service_load_pid_file(Service *s, bool may_warn) {
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         if (!s->pid_file)
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                 return -ENOENT;
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-        r = read_one_line_file(s->pid_file, &k);
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-        if (r < 0) {
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-                if (may_warn)
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-                        log_unit_info(UNIT(s)->id, "PID file %s not readable (yet?) after %s.", s->pid_file, service_state_to_string(s->state));
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-                return r;
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-        }
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+        prio = may_warn ? LOG_INFO : LOG_DEBUG;
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+
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+        fd = chase_symlinks(s->pid_file, NULL, CHASE_OPEN|CHASE_SAFE, NULL);
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+        if (fd == -EPERM)
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+                return log_unit_full(UNIT(s)->id, prio, "Permission denied while opening PID file or unsafe symlink chain: %s", s->pid_file);
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+        if (fd < 0)
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+                return log_unit_full(UNIT(s)->id, prio, "Can't open PID file %s (yet?) after %s: %m", s->pid_file, service_state_to_string(s->state));
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+
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+        /* Let's read the PID file now that we chased it down. But we need to convert the O_PATH fd chase_symlinks() returned us into a proper fd first. */
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+        xsprintf(procfs, "/proc/self/fd/%i", fd);
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+        r = read_one_line_file(procfs, &k);
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+        if (r < 0)
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+                return log_unit_error_errno(UNIT(s)->id, r, "Can't convert PID files %s O_PATH file descriptor to proper file descriptor: %m", s->pid_file);
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         r = parse_pid(k, &pid;;
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-        if (r < 0) {
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-                if (may_warn)
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-                        log_unit_info_errno(UNIT(s)->id, r, "Failed to read PID from file %s: %m", s->pid_file);
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+        if (r < 0)
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+                return log_unit_full(UNIT(s)->id, prio, "Failed to parse PID from file %s: %m", s->pid_file);
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+
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+        if (s->main_pid_known && pid == s->main_pid)
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+                return 0;
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+
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+        r = service_is_suitable_main_pid(s, pid, prio);
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+        if (r < 0)
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                 return r;
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-        }
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+        if (r == 0) {
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+                struct stat st;
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-        if (!pid_is_alive(pid)) {
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-                if (may_warn)
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-                        log_unit_info(UNIT(s)->id, "PID "PID_FMT" read from file %s does not exist or is a zombie.", pid, s->pid_file);
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-                return -ESRCH;
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+                /* Hmm, it's not clear if the new main PID is safe. Let's allow this if the PID file is owned by root */
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+
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+                if (fstat(fd, &st) < 0)
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+                        return log_unit_error_errno(UNIT(s)->id, errno, "Failed to fstat() PID file O_PATH fd: %m");
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+
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+                if (st.st_uid != 0) {
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+                        log_unit_error(UNIT(s)->id, "New main PID "PID_FMT" does not belong to service, and PID file is not owned by root. Refusing.", pid);
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+                        return -EPERM;
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+                }
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+
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+                log_unit_debug(UNIT(s)->id, "New main PID "PID_FMT" does not belong to service, but we'll accept it since PID file is owned by root.", pid);
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         }
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         if (s->main_pid_known) {
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-                if (pid == s->main_pid)
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-                        return 0;
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-
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                 log_unit_debug(UNIT(s)->id, "Main PID changing: "PID_FMT" -> "PID_FMT, s->main_pid, pid);
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                 service_unwatch_main_pid(s);
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@@ -752,7 +805,7 @@ static int service_load_pid_file(Service *s, bool may_warn) {
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                 return r;
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         }
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-        return 0;
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+        return 1;
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 }
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 static int service_search_main_pid(Service *s) {
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@@ -2584,7 +2637,7 @@ static void service_sigchld_event(Unit *u, pid_t pid, int code, int status) {
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                 /* Forking services may occasionally move to a new PID.
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                  * As long as they update the PID file before exiting the old
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                  * PID, they're fine. */
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-                if (service_load_pid_file(s, false) == 0)
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+                if (service_load_pid_file(s, false) > 0)
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                         return;
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                 s->main_pid = 0;
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@@ -2957,42 +3010,73 @@ static int service_dispatch_watchdog(sd_event_source *source, usec_t usec, void
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         return 0;
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 }
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-static void service_notify_message(Unit *u, pid_t pid, char **tags, FDSet *fds) {
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+static bool service_notify_message_authorized(Service *s, pid_t pid, char **tags, FDSet *fds) {
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+        assert(s);
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+
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+        if (s->notify_access == NOTIFY_NONE) {
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+                log_unit_warning(UNIT(s)->id, "Got notification message from PID "PID_FMT", but reception is disabled.", pid);
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+                return false;
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+        }
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+
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+        if (s->notify_access == NOTIFY_MAIN && pid != s->main_pid) {
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+                if (s->main_pid != 0)
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+                        log_unit_warning(UNIT(s)->id, "Got notification message from PID "PID_FMT", but reception only permitted for main PID "PID_FMT, pid, s->main_pid);
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+                else
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+                        log_unit_warning(UNIT(s)->id, "Got notification message from PID "PID_FMT", but reception only permitted for main PID which is currently not known", pid);
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+
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+                return false;
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+        }
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+
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+        return true;
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+}
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+
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+static void service_notify_message(
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+                Unit *u,
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+                const struct ucred *ucred,
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+                char **tags,
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+                FDSet *fds) {
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         Service *s = SERVICE(u);
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-        _cleanup_free_ char *cc = NULL;
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         bool notify_dbus = false;
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         const char *e;
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+        int r;
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         assert(u);
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+        assert(ucred);
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-        cc = strv_join(tags, ", ");
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-        log_unit_debug(u->id, "%s: Got notification message from PID "PID_FMT" (%s)",
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-                       u->id, pid, isempty(cc) ? "n/a" : cc);
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+        if (!service_notify_message_authorized(SERVICE(u), ucred->pid, tags, fds))
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+                return;
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         if (s->notify_access == NOTIFY_NONE) {
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-                log_unit_warning(u->id, "%s: Got notification message from PID "PID_FMT", but reception is disabled.", u->id, pid);
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-                return;
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-        }
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+                _cleanup_free_ char *cc = NULL;
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-        if (s->notify_access == NOTIFY_MAIN && pid != s->main_pid) {
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-                if (s->main_pid != 0)
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-                        log_unit_warning(u->id, "%s: Got notification message from PID "PID_FMT", but reception only permitted for main PID "PID_FMT, u->id, pid, s->main_pid);
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-                else
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-                        log_unit_debug(u->id, "%s: Got notification message from PID "PID_FMT", but reception only permitted for main PID which is currently not known", u->id, pid);
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-                return;
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+                cc = strv_join(tags, ", ");
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+                log_unit_debug(u->id, "Got notification message from PID "PID_FMT" (%s)", ucred->pid, isempty(cc) ? "n/a" : cc);
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         }
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         /* Interpret MAINPID= */
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         e = strv_find_startswith(tags, "MAINPID=");
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         if (e && IN_SET(s->state, SERVICE_START, SERVICE_START_POST, SERVICE_RUNNING, SERVICE_RELOAD)) {
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-                if (parse_pid(e, &pid) < 0)
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-                        log_unit_warning(u->id, "Failed to parse MAINPID= field in notification message: %s", e);
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-                else {
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-                        log_unit_debug(u->id, "%s: got MAINPID=%s", u->id, e);
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+                pid_t new_main_pid;
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-                        service_set_main_pid(s, pid);
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-                        unit_watch_pid(UNIT(s), pid);
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-                        notify_dbus = true;
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+                if (parse_pid(e, &new_main_pid) < 0)
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+                        log_unit_warning(u->id, "Failed to parse MAINPID= field in notification message, ignoring: %s", e);
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+                else if (!s->main_pid_known || new_main_pid != s->main_pid) {
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+
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+                        r = service_is_suitable_main_pid(s, new_main_pid, LOG_WARNING);
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+                        if (r == 0) {
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+                                /* The new main PID is a bit suspicous, which is OK if the sender is privileged. */
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+
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+                                if (ucred->uid == 0) {
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+                                        log_unit_debug(u->id, "New main PID "PID_FMT" does not belong to service, but we'll accept it as the request to change it came from a privileged process.", new_main_pid);
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+                                        r = 1;
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+                                } else
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+                                        log_unit_debug(u->id, "New main PID "PID_FMT" does not belong to service, refusing.", new_main_pid);
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+                        }
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+                        if (r > 0) {
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+                                service_set_main_pid(s, new_main_pid);
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+                                unit_watch_pid(UNIT(s), new_main_pid);
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+                                notify_dbus = true;
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+                        }
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                 }
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         }
c62b8e
 
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diff --git a/src/core/unit.h b/src/core/unit.h
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index dfec9cea01..091ef7596e 100644
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--- a/src/core/unit.h
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+++ b/src/core/unit.h
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@@ -376,7 +376,7 @@ struct UnitVTable {
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         void (*notify_cgroup_empty)(Unit *u);
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         /* Called whenever a process of this unit sends us a message */
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-        void (*notify_message)(Unit *u, pid_t pid, char **tags, FDSet *fds);
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+        void (*notify_message)(Unit *u, const struct ucred *ucred, char **tags, FDSet *fds);
c62b8e
 
c62b8e
         /* Called whenever a name this Unit registered for comes or
c62b8e
          * goes away. */
c62b8e
diff --git a/test/TEST-20-MAINPIDGAMES/Makefile b/test/TEST-20-MAINPIDGAMES/Makefile
c62b8e
new file mode 120000
c62b8e
index 0000000000..e9f93b1104
c62b8e
--- /dev/null
c62b8e
+++ b/test/TEST-20-MAINPIDGAMES/Makefile
c62b8e
@@ -0,0 +1 @@
c62b8e
+../TEST-01-BASIC/Makefile
c62b8e
\ No newline at end of file
c62b8e
diff --git a/test/TEST-20-MAINPIDGAMES/test.sh b/test/TEST-20-MAINPIDGAMES/test.sh
c62b8e
new file mode 100755
c62b8e
index 0000000000..733532b718
c62b8e
--- /dev/null
c62b8e
+++ b/test/TEST-20-MAINPIDGAMES/test.sh
c62b8e
@@ -0,0 +1,81 @@
c62b8e
+#!/bin/bash
c62b8e
+# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
c62b8e
+# ex: ts=8 sw=4 sts=4 et filetype=sh
c62b8e
+TEST_DESCRIPTION="test changing main PID"
c62b8e
+
c62b8e
+. $TEST_BASE_DIR/test-functions
c62b8e
+
c62b8e
+check_result_qemu() {
c62b8e
+    ret=1
c62b8e
+    mkdir -p $TESTDIR/root
c62b8e
+    mount ${LOOPDEV}p1 $TESTDIR/root
c62b8e
+    [[ -e $TESTDIR/root/testok ]] && ret=0
c62b8e
+    [[ -f $TESTDIR/root/failed ]] && cp -a $TESTDIR/root/failed $TESTDIR
c62b8e
+    [[ -f $TESTDIR/root/var/log/journal ]] && cp -a $TESTDIR/root/var/log/journal $TESTDIR
c62b8e
+    umount $TESTDIR/root
c62b8e
+    [[ -f $TESTDIR/failed ]] && cat $TESTDIR/failed
c62b8e
+    ls -l $TESTDIR/journal/*/*.journal
c62b8e
+    test -s $TESTDIR/failed && ret=$(($ret+1))
c62b8e
+    return $ret
c62b8e
+}
c62b8e
+
c62b8e
+test_run() {
c62b8e
+    if run_qemu; then
c62b8e
+        check_result_qemu || return 1
c62b8e
+    else
c62b8e
+        dwarn "can't run QEMU, skipping"
c62b8e
+    fi
c62b8e
+    if check_nspawn; then
c62b8e
+        run_nspawn
c62b8e
+        check_result_nspawn || return 1
c62b8e
+    else
c62b8e
+        dwarn "can't run systemd-nspawn, skipping"
c62b8e
+    fi
c62b8e
+    return 0
c62b8e
+}
c62b8e
+
c62b8e
+test_setup() {
c62b8e
+    create_empty_image
c62b8e
+    mkdir -p $TESTDIR/root
c62b8e
+    mount ${LOOPDEV}p1 $TESTDIR/root
c62b8e
+
c62b8e
+    (
c62b8e
+        LOG_LEVEL=5
c62b8e
+        eval $(udevadm info --export --query=env --name=${LOOPDEV}p2)
c62b8e
+
c62b8e
+        setup_basic_environment
c62b8e
+        inst_binary cut
c62b8e
+        inst_binary useradd
c62b8e
+        inst /etc/login.defs
c62b8e
+
c62b8e
+        # setup the testsuite service
c62b8e
+        cat >$initdir/etc/systemd/system/testsuite.service <
c62b8e
+[Unit]
c62b8e
+Description=Testsuite service
c62b8e
+
c62b8e
+[Service]
c62b8e
+ExecStart=/bin/bash -x /testsuite.sh
c62b8e
+Type=oneshot
c62b8e
+StandardOutput=tty
c62b8e
+StandardError=tty
c62b8e
+NotifyAccess=all
c62b8e
+EOF
c62b8e
+        cp testsuite.sh $initdir/
c62b8e
+
c62b8e
+        useradd -R $initdir -U -u 1234 test
c62b8e
+
c62b8e
+        setup_testsuite
c62b8e
+    )
c62b8e
+    setup_nspawn_root
c62b8e
+
c62b8e
+    ddebug "umount $TESTDIR/root"
c62b8e
+    umount $TESTDIR/root
c62b8e
+}
c62b8e
+
c62b8e
+test_cleanup() {
c62b8e
+    umount $TESTDIR/root 2>/dev/null
c62b8e
+    [[ $LOOPDEV ]] && losetup -d $LOOPDEV
c62b8e
+    return 0
c62b8e
+}
c62b8e
+
c62b8e
+do_test "$@"
c62b8e
diff --git a/test/TEST-20-MAINPIDGAMES/testsuite.sh b/test/TEST-20-MAINPIDGAMES/testsuite.sh
c62b8e
new file mode 100755
c62b8e
index 0000000000..d4ad63865c
c62b8e
--- /dev/null
c62b8e
+++ b/test/TEST-20-MAINPIDGAMES/testsuite.sh
c62b8e
@@ -0,0 +1,189 @@
c62b8e
+#!/bin/bash
c62b8e
+# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
c62b8e
+# ex: ts=8 sw=4 sts=4 et filetype=sh
c62b8e
+set -ex
c62b8e
+set -o pipefail
c62b8e
+
c62b8e
+systemctl_show_value() {
c62b8e
+    systemctl show "$@" | cut -d = -f 2-
c62b8e
+}
c62b8e
+
c62b8e
+systemd-analyze set-log-level debug
c62b8e
+
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+# Start a test process inside of our own cgroup
c62b8e
+sleep infinity &
c62b8e
+INTERNALPID=$!
c62b8e
+disown
c62b8e
+
c62b8e
+# Start a test process outside of our own cgroup
c62b8e
+systemd-run -p User=test --unit=sleep.service /bin/sleep infinity
c62b8e
+EXTERNALPID=`systemctl_show_value -p MainPID sleep.service`
c62b8e
+
c62b8e
+# Update our own main PID to the external test PID, this should work
c62b8e
+systemd-notify MAINPID=$EXTERNALPID
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $EXTERNALPID
c62b8e
+
c62b8e
+# Update our own main PID to the internal test PID, this should work, too
c62b8e
+systemd-notify MAINPID=$INTERNALPID
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $INTERNALPID
c62b8e
+
c62b8e
+# Update it back to our own PID, this should also work
c62b8e
+systemd-notify MAINPID=$$
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+# Try to set it to PID 1, which it should ignore, because that's the manager
c62b8e
+systemd-notify MAINPID=1
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+# Try to set it to PID 0, which is invalid and should be ignored
c62b8e
+systemd-notify MAINPID=0
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+# Try to set it to a valid but non-existing PID, which should be ignored. (Note
c62b8e
+# that we set the PID to a value well above any known /proc/sys/kernel/pid_max,
c62b8e
+# which means we can be pretty sure it doesn't exist by coincidence)
c62b8e
+systemd-notify MAINPID=1073741824
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+# Change it again to the external PID, without priviliges this time. This should be ignored, because the PID is from outside of our cgroup and we lack privileges.
c62b8e
+systemd-notify --uid=1000 MAINPID=$EXTERNALPID
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+# Change it again to the internal PID, without priviliges this time. This should work, as the process is on our cgroup, and that's enough even if we lack privileges.
c62b8e
+systemd-notify --uid=1000 MAINPID=$INTERNALPID
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $INTERNALPID
c62b8e
+
c62b8e
+# Update it back to our own PID, this should also work
c62b8e
+systemd-notify --uid=1000 MAINPID=$$
c62b8e
+test `systemctl_show_value -p MainPID testsuite.service` -eq $$
c62b8e
+
c62b8e
+cat >/tmp/mainpid.sh <
c62b8e
+#!/bin/bash
c62b8e
+
c62b8e
+set -eux
c62b8e
+set -o pipefail
c62b8e
+
c62b8e
+# Create a number of children, and make one the main one
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+MAINPID=\$!
c62b8e
+disown
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+echo \$MAINPID > /run/mainpidsh/pid
c62b8e
+EOF
c62b8e
+chmod +x /tmp/mainpid.sh
c62b8e
+
c62b8e
+cat > /etc/systemd/system/mainpidsh.service <
c62b8e
+[Unit]
c62b8e
+Description=MainPID test 1 service
c62b8e
+
c62b8e
+[Service]
c62b8e
+StandardOutput=tty
c62b8e
+StandardError=tty
c62b8e
+Type=forking
c62b8e
+RuntimeDirectory=mainpidsh
c62b8e
+PIDFile=/run/mainpidsh/pid
c62b8e
+ExecStart=/tmp/mainpid.sh
c62b8e
+EOF
c62b8e
+
c62b8e
+systemctl daemon-reload
c62b8e
+systemctl start mainpidsh.service
c62b8e
+test `systemctl_show_value -p MainPID mainpidsh.service` -eq `cat /run/mainpidsh/pid`
c62b8e
+
c62b8e
+cat >/tmp/mainpid2.sh <
c62b8e
+#!/bin/bash
c62b8e
+
c62b8e
+set -eux
c62b8e
+set -o pipefail
c62b8e
+
c62b8e
+# Create a number of children, and make one the main one
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+MAINPID=\$!
c62b8e
+disown
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+echo \$MAINPID > /run/mainpidsh2/pid
c62b8e
+chown 1001:1001 /run/mainpidsh2/pid
c62b8e
+EOF
c62b8e
+chmod +x /tmp/mainpid2.sh
c62b8e
+
c62b8e
+cat > /etc/systemd/system/mainpidsh2.service <
c62b8e
+[Unit]
c62b8e
+Description=MainPID test 2 service
c62b8e
+
c62b8e
+[Service]
c62b8e
+StandardOutput=tty
c62b8e
+StandardError=tty
c62b8e
+Type=forking
c62b8e
+RuntimeDirectory=mainpidsh2
c62b8e
+PIDFile=/run/mainpidsh2/pid
c62b8e
+ExecStart=/tmp/mainpid2.sh
c62b8e
+EOF
c62b8e
+
c62b8e
+systemctl daemon-reload
c62b8e
+systemctl start mainpidsh2.service
c62b8e
+test `systemctl_show_value -p MainPID mainpidsh2.service` -eq `cat /run/mainpidsh2/pid`
c62b8e
+
c62b8e
+cat >/dev/shm/mainpid3.sh <
c62b8e
+#!/bin/bash
c62b8e
+
c62b8e
+set -eux
c62b8e
+set -o pipefail
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+sleep infinity &
c62b8e
+disown
c62b8e
+
c62b8e
+# Let's try to play games, and link up a privileged PID file
c62b8e
+ln -s ../mainpidsh/pid /run/mainpidsh3/pid
c62b8e
+
c62b8e
+# Quick assertion that the link isn't dead
c62b8e
+test -f /run/mainpidsh3/pid
c62b8e
+EOF
c62b8e
+chmod 755 /dev/shm/mainpid3.sh
c62b8e
+
c62b8e
+cat > /etc/systemd/system/mainpidsh3.service <
c62b8e
+[Unit]
c62b8e
+Description=MainPID test 3 service
c62b8e
+
c62b8e
+[Service]
c62b8e
+StandardOutput=tty
c62b8e
+StandardError=tty
c62b8e
+Type=forking
c62b8e
+RuntimeDirectory=mainpidsh3
c62b8e
+PIDFile=/run/mainpidsh3/pid
c62b8e
+User=test
c62b8e
+TimeoutStartSec=2s
c62b8e
+ExecStart=/dev/shm/mainpid3.sh
c62b8e
+EOF
c62b8e
+
c62b8e
+systemctl daemon-reload
c62b8e
+systemctl start mainpidsh3.service
c62b8e
+
c62b8e
+# Test that this failed due to timeout, and not some other error
c62b8e
+# test `systemctl_show_value -p Result mainpidsh3.service` = timeout
c62b8e
+# Just check that there is no MainPID => the pid file was ignored
c62b8e
+test `systemctl_show_value -p MainPID mainpidsh3.service` -eq 0
c62b8e
+
c62b8e
+systemd-analyze set-log-level info
c62b8e
+
c62b8e
+echo OK > /testok
c62b8e
+
c62b8e
+exit 0
c62b8e
diff --git a/test/test-functions b/test/test-functions
c62b8e
index 78e725d5b9..e50ce556fd 100644
c62b8e
--- a/test/test-functions
c62b8e
+++ b/test/test-functions
c62b8e
@@ -12,7 +12,7 @@ if ! ROOTLIBDIR=$(pkg-config --variable=systemdutildir systemd); then
c62b8e
     ROOTLIBDIR=/usr/lib/systemd
c62b8e
 fi
c62b8e
 
c62b8e
-BASICTOOLS="sh bash setsid loadkeys setfont login sulogin gzip sleep echo mount umount cryptsetup date dmsetup modprobe"
c62b8e
+BASICTOOLS="test sh bash setsid loadkeys setfont login sulogin gzip sleep echo mount umount cryptsetup date dmsetup modprobe chmod chown ln"
c62b8e
 DEBUGTOOLS="df free ls stty cat ps ln ip route dmesg dhclient mkdir cp ping dhclient strace less grep id tty touch du sort hostname"
c62b8e
 
c62b8e
 function find_qemu_bin() {