From 7a463eb3f7280e8db04e0e6dbd308d9c35c34823 Mon Sep 17 00:00:00 2001
From: "Sergey G. Brester" <serg.brester@sebres.de>
Date: Wed, 3 Apr 2019 23:58:23 +0200
Subject: [PATCH] closes gh-2395: safe conversion of `SYSLOG_PID` or `_PID` (if
 journal entry contains a string instead of numeric)

---
 fail2ban/server/filtersystemd.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/fail2ban/server/filtersystemd.py b/fail2ban/server/filtersystemd.py
index 73db618e..15c90548 100644
--- a/fail2ban/server/filtersystemd.py
+++ b/fail2ban/server/filtersystemd.py
@@ -204,7 +204,14 @@ class FilterSystemd(JournalFilter): # pragma: systemd no cover
 			if not v:
 				v = logentry.get('_PID')
 			if v:
-				logelements[-1] += ("[%i]" % v)
+				try: # [integer] (if already numeric):
+					v = "[%i]" % v
+				except TypeError:
+					try: # as [integer] (try to convert to int):
+						v = "[%i]" % int(v, 0)
+					except (TypeError, ValueError): # fallback - [string] as it is
+						v = "[%s]" % v
+				logelements[-1] += v
 			logelements[-1] += ":"
 			if logelements[-1] == "kernel:":
 				if '_SOURCE_MONOTONIC_TIMESTAMP' in logentry: