From 7a4a54db97ab564f051ce4c5ea01fc4e1dd28cce Mon Sep 17 00:00:00 2001
From: Axel Burri <axel@tty0.ch>
Date: Sat, 19 Nov 2022 19:31:57 +0100
Subject: [PATCH] btrbk: disallow newline in files

While most functionality works fine, raw backups fail to write correct
"FILE=" information in info sidecar.

Disallowing newlines in files is a good idea in general.
---
 btrbk | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/btrbk b/btrbk
index 6cecf11..6dbd79b 100755
--- a/btrbk
+++ b/btrbk
@@ -3768,7 +3768,10 @@ sub check_file($$;@)
     die("accept_type must contain either 'relative' or 'absolute'");
   }
 
-  # check directory traversal
+  if($file =~ /\n/) {
+    ERROR "Unsupported newline in file ${error_statement}: " . ($file =~ s/\n/\\n/gr) if(defined($error_statement));
+    return undef;
+  }
   if(($file =~ /^\.\.$/) || ($file =~ /^\.\.\//) || ($file =~ /\/\.\.\//) || ($file =~ /\/\.\.$/)) {
     ERROR "Illegal directory traversal ${error_statement}: $file" if(defined($error_statement));
     return undef;