[PULL 5/7] fuzz: add virtio-9p configurations for fuzzing

From: Alexander Bulekov <alxndr@bu.edu>
To: qemu-devel@nongnu.org
Cc: Laurent Vivier <lvivier@redhat.com>,
	Peter Maydell <peter.maydell@linaro.org>,
	Thomas Huth <thuth@redhat.com>, Alexander Bulekov <alxndr@bu.edu>,
	Darren Kenny <darren.kenny@oracle.com>,
	Bandan Das <bsd@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Subject: [PULL 5/7] fuzz: add virtio-9p configurations for fuzzing
Date: Wed, 20 Jan 2021 12:35:31 -0500	[thread overview]
Message-ID: <20210120173536.265601-10-alxndr@bu.edu> (raw)
In-Reply-To: <20210120173536.265601-1-alxndr@bu.edu>

virtio-9p devices are often used to expose a virtual-filesystem to the
guest. There have been some bugs reported in this device, such as
CVE-2018-19364, and CVE-2021-20181. We should fuzz this device

This patch adds two virtio-9p configurations:
 * One with the widely used -fsdev local driver. This driver leaks some
   state in the form of files/directories created in the shared dir.
 * One with the synth driver. While it is not used in the real world, this
   driver won't leak leak state between fuzz inputs.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
---
 tests/qtest/fuzz/generic_fuzz_configs.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/qtest/fuzz/generic_fuzz_configs.h b/tests/qtest/fuzz/generic_fuzz_configs.h
index 1a133655ee..f99657cdbc 100644
--- a/tests/qtest/fuzz/generic_fuzz_configs.h
+++ b/tests/qtest/fuzz/generic_fuzz_configs.h
@@ -19,6 +19,16 @@ typedef struct generic_fuzz_config {
     gchar* (*argfunc)(void); /* Result must be freeable by g_free() */
 } generic_fuzz_config;
 
+static inline gchar *generic_fuzzer_virtio_9p_args(void){
+    char tmpdir[] = "/tmp/qemu-fuzz.XXXXXX";
+    g_assert_nonnull(mkdtemp(tmpdir));
+
+    return g_strdup_printf("-machine q35 -nodefaults "
+    "-device virtio-9p,fsdev=hshare,mount_tag=hshare "
+    "-fsdev local,id=hshare,path=%s,security_model=mapped-xattr,"
+    "writeout=immediate,fmode=0600,dmode=0700", tmpdir);
+}
+
 const generic_fuzz_config predefined_configs[] = {
     {
         .name = "virtio-net-pci-slirp",
@@ -60,6 +70,16 @@ const generic_fuzz_config predefined_configs[] = {
         .name = "virtio-mouse",
         .args = "-machine q35 -nodefaults -device virtio-mouse",
         .objects = "virtio*",
+    },{
+        .name = "virtio-9p",
+        .argfunc = generic_fuzzer_virtio_9p_args,
+        .objects = "virtio*",
+    },{
+        .name = "virtio-9p-synth",
+        .args = "-machine q35 -nodefaults "
+        "-device virtio-9p,fsdev=hshare,mount_tag=hshare "
+        "-fsdev synth,id=hshare",
+        .objects = "virtio*",
     },{
         .name = "e1000",
         .args = "-M q35 -nodefaults "
-- 
2.28.0


