From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 21 May 2021 14:31:52 +0000 (+0200)
Subject: fileio: read_virtual_file(): exit once the max_size limit is reached
X-Git-Tag: v249-rc1~177^2~5
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=136f12a26ae0b6930094574f55e9399b120e54c0;p=thirdparty%2Fsystemd.git

fileio: read_virtual_file(): exit once the max_size limit is reached

Alternative to: #19682
---

diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 7bb1e8a8c6e..cb8f5b0b184 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -450,6 +450,13 @@ int read_virtual_file(const char *filename, size_t max_size, char **ret_contents
                 if (n <= size)
                         break;
 
+                /* If a maximum size is specified and we already read as much, no need to try again */
+                if (max_size != SIZE_MAX && n >= max_size) {
+                        n = max_size;
+                        truncated = true;
+                        break;
+                }
+
                 /* Hmm... either we read too few bytes from /proc or less likely the content
                  * of the file might have been changed (and is now bigger) while we were
                  * processing, let's try again either with a bigger guessed size or the new