From d76079efefd68e7d46966db305988034874cc01e Mon Sep 17 00:00:00 2001
From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Dec 15 2020 17:55:08 +0000
Subject: fuzz-journal-stream: avoid assertion failure on samples which don't fit in pipe


Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=11587.
We had a sample which was large enough that write(2) failed to push all the
data into the pipe, and an assert failed. The code could be changed to use
a loop, but then we'd need to interleave writes and sd_event_run (to process
the journal). I don't think the complexity is worth it — fuzzing works best
if the sample is not too huge anyway. So let's just reject samples above 64k,
and tell oss-fuzz about this limit.

(cherry picked from commit eafadd069c4e30ed62173123326a7237448615d1)

Resolves: #1764560

patch_name: 0264-fuzz-journal-stream-avoid-assertion-failure-on-sampl.patch
present_in_specfile: true
location_in_specfile: 264
squash_commits: true

---

diff --git a/src/fuzz/fuzz-journald-stream.c b/src/fuzz/fuzz-journald-stream.c
index 247c088..693b197 100644
--- a/src/fuzz/fuzz-journald-stream.c
+++ b/src/fuzz/fuzz-journald-stream.c
@@ -14,7 +14,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         StdoutStream *stream;
         int v;
 
-        if (size == 0)
+        if (size == 0 || size > 65536)
                 return 0;
 
         if (!getenv("SYSTEMD_LOG_LEVEL"))
diff --git a/src/fuzz/fuzz-journald-stream.options b/src/fuzz/fuzz-journald-stream.options
new file mode 100644
index 0000000..678d526
--- /dev/null
+++ b/src/fuzz/fuzz-journald-stream.options
@@ -0,0 +1,2 @@
+[libfuzzer]
+max_len = 65536