From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 29 Dec 2017 17:13:38 +0000 (+0100)
Subject: pager,agent: insist that we are called from the main thread
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=6ee75904e748798e2138425abe37068ed0c7c8d7;p=elogind.git

pager,agent: insist that we are called from the main thread

We maintain static process-wide variables in these subsystems without
locking, hence let's refuse operation unless we are called from the main
thread (which we do anyway) just as a safety precaution.
---

diff --git a/src/shared/pager.c b/src/shared/pager.c
index b34cf2c00..7a19d4bb1 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -73,6 +73,9 @@ int pager_open(bool no_pager, bool jump_to_end) {
         if (terminal_is_dumb())
                 return 0;
 
+        if (!is_main_thread())
+                return -EPERM;
+
         pager = getenv("SYSTEMD_PAGER");
         if (!pager)
                 pager = getenv("PAGER");
diff --git a/src/shared/spawn-polkit-agent.c b/src/shared/spawn-polkit-agent.c
index 886248b9f..3c93c79ce 100644
--- a/src/shared/spawn-polkit-agent.c
+++ b/src/shared/spawn-polkit-agent.c
@@ -52,6 +52,9 @@ int polkit_agent_open(void) {
         if (!isatty(STDIN_FILENO))
                 return 0;
 
+        if (!is_main_thread())
+                return -EPERM;
+
         if (pipe2(pipe_fd, 0) < 0)
                 return -errno;