From 9576fa3ecf91fd4703e2180ac080fd975292730f Mon Sep 17 00:00:00 2001
From: hese10 <heikki.kemppainen@nokia.com>
Date: Wed, 12 Oct 2016 19:40:28 +0300
Subject: [PATCH] Avoid forever loop for journalctl --list-boots command
 (#4278)

When date is changed in system to future and normal user logs to new
journal file, and then date is changed back to present time, the
"journalctl --list-boot" command goes to forever loop. This commit tries
to fix this problem by checking first the boot id list if the found boot
id was already in that list. If it is found, then stopping the boot id
find loop.

(cherry picked from commit ec02a6c90a5d8b234db534ce3f8f1901f8532057)

Conflicts:
	src/journal/journalctl.c
Related: #1294516
---
 src/journal/journalctl.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c
index 723854a2e..c771cff8b 100644
--- a/src/journal/journalctl.c
+++ b/src/journal/journalctl.c
@@ -1039,7 +1039,7 @@ static int get_boots(
 
         bool skip_once;
         int r, count = 0;
-        BootId *head = NULL, *tail = NULL;
+        BootId *head = NULL, *tail = NULL, *id;
         const bool advance_older = query_ref_boot && ref_boot_offset <= 0;
         sd_id128_t previous_boot_id;
 
@@ -1121,6 +1121,13 @@ static int get_boots(
                                 break;
                         }
                 } else {
+                        LIST_FOREACH(boot_list, id, head) {
+                                if (sd_id128_equal(id->id, current->id)) {
+                                        /* boot id already stored, something wrong with the journal files */
+                                        /* exiting as otherwise this problem would cause forever loop */
+                                        goto finish;
+                                }
+                        }
                         LIST_INSERT_AFTER(boot_list, head, tail, current);
                         tail = current;
                         current = NULL;