From c797789c1f45dc76f4cf933ad3e3d24376c2b76e Mon Sep 17 00:00:00 2001
From: Stefan Schantl <stefan.schantl@ipfire.org>
Date: Wed, 10 May 2023 11:52:03 +0200
Subject: [PATCH] backup.cgi: Read and deliver the requested backup in pieces

Read-in the requested backup file line by line and directly deliver this
as stream to the client.

This fixes the problem with very big backups on systems with very
limited RAM, which resulted in an OOM kill of the CGI and delivery
process.

Fixes #13096.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>
Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>
---
 html/cgi-bin/backup.cgi | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/html/cgi-bin/backup.cgi b/html/cgi-bin/backup.cgi
index 1c01cb286f..3888ccbff9 100644
--- a/html/cgi-bin/backup.cgi
+++ b/html/cgi-bin/backup.cgi
@@ -366,6 +366,13 @@ sub deliver_file() {
 
 	# Deliver content
 	open(FILE, "<$file") or die "Unable to open $file: $!";
-	print <FILE>;
+
+	# Read the file line by line and send it
+	# to the client.
+	while (<FILE>) {
+		print $_;
+	}
+
+	# Close file handle.
 	close(FILE);
 }
-- 
2.39.5