systemd/SOURCES/0388-fuzz-compress-add-fuzzer-for-compression-and-decompr.patch
2021-09-10 05:03:39 +00:00

119 lines
3.8 KiB
Diff

From 242273e1afd456e86ebc48d7d601cb28297f8efb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Tue, 30 Oct 2018 09:02:26 +0100
Subject: [PATCH] fuzz-compress: add fuzzer for compression and decompression
(cherry picked from commit 029427043b2e0523a21f54374f872b23cf744350)
Resolves: #1843871
---
src/fuzz/fuzz-compress.c | 80 ++++++++++++++++++++++++++++++++++++++++
src/fuzz/meson.build | 7 +++-
2 files changed, 86 insertions(+), 1 deletion(-)
create mode 100644 src/fuzz/fuzz-compress.c
diff --git a/src/fuzz/fuzz-compress.c b/src/fuzz/fuzz-compress.c
new file mode 100644
index 0000000000..9c5dfc92c0
--- /dev/null
+++ b/src/fuzz/fuzz-compress.c
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+
+#include "alloc-util.h"
+#include "compress.h"
+#include "fuzz.h"
+
+static int compress(int alg,
+ const void *src, uint64_t src_size,
+ void *dst, size_t dst_alloc_size, size_t *dst_size) {
+
+ if (alg == OBJECT_COMPRESSED_LZ4)
+ return compress_blob_lz4(src, src_size, dst, dst_alloc_size, dst_size);
+ if (alg == OBJECT_COMPRESSED_XZ)
+ return compress_blob_xz(src, src_size, dst, dst_alloc_size, dst_size);
+ return -EOPNOTSUPP;
+}
+
+typedef struct header {
+ uint32_t alg:2; /* We have only two compression algorithms so far, but we might add
+ * more in the future. Let's make this a bit wider so our fuzzer
+ * cases remain stable in the future. */
+ uint32_t sw_len;
+ uint32_t sw_alloc;
+ uint32_t reserved[3]; /* Extra space to keep fuzz cases stable in case we need to
+ * add stuff in the future. */
+ uint8_t data[];
+} header;
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+ _cleanup_free_ void *buf = NULL, *buf2 = NULL;
+ int r;
+
+ if (size < offsetof(header, data) + 1)
+ return 0;
+
+ const header *h = (struct header*) data;
+ const size_t data_len = size - offsetof(header, data);
+
+ int alg = h->alg;
+
+ /* We don't want to fill the logs with messages about parse errors.
+ * Disable most logging if not running standalone */
+ if (!getenv("SYSTEMD_LOG_LEVEL"))
+ log_set_max_level(LOG_CRIT);
+
+ log_info("Using compression %s, data size=%zu",
+ object_compressed_to_string(alg) ?: "(none)",
+ data_len);
+
+ buf = malloc(MAX(size, 128u)); /* Make the buffer a bit larger for very small data */
+ if (!buf) {
+ log_oom();
+ return 0;
+ }
+
+ size_t csize;
+ r = compress(alg, h->data, data_len, buf, size, &csize);
+ if (r < 0) {
+ log_error_errno(r, "Compression failed: %m");
+ return 0;
+ }
+
+ log_debug("Compressed %zu bytes to → %zu bytes", data_len, csize);
+
+ size_t sw_alloc = MAX(h->sw_alloc, 1u);
+ buf2 = malloc(sw_alloc);
+ if (!buf) {
+ log_oom();
+ return 0;
+ }
+
+ size_t sw_len = MIN(data_len - 1, h->sw_len);
+
+ r = decompress_startswith(alg, buf, csize, &buf2, &sw_alloc, h->data, sw_len, h->data[sw_len]);
+ assert_se(r > 0);
+
+ return 0;
+}
diff --git a/src/fuzz/meson.build b/src/fuzz/meson.build
index 5315d2771c..b8d5979d3c 100644
--- a/src/fuzz/meson.build
+++ b/src/fuzz/meson.build
@@ -73,8 +73,13 @@ fuzzers += [
[libsystemd_journal_remote,
libshared],
[]],
+
[['src/fuzz/fuzz-fido-id-desc.c',
'src/udev/fido_id/fido_id_desc.c'],
[],
- []]
+ []],
+
+ [['src/fuzz/fuzz-compress.c'],
+ [libshared],
+ []],
]