Merge pull request #10788 from evverx/fuzz-kmsg

tests: add a fuzzer for dev_kmsg_record

5 files changed, 38 insertions, 3 deletions

diff --git a/src/basic/escape.c b/src/basic/escape.c
index 5004763d97..5f715156fb 100644
--- a/src/basic/escape.c
+++ b/src/basic/escape.c
@@ -106,7 +106,6 @@ int cunescape_one(const char *p, size_t length, char32_t *ret, bool *eight_bit)
         int r = 1;
 
         assert(p);
-        assert(*p);
         assert(ret);
 
         /* Unescapes C style. Returns the unescaped character in ret.
diff --git a/src/fuzz/fuzz-journald-kmsg.c b/src/fuzz/fuzz-journald-kmsg.c
new file mode 100644
index 0000000000..5d99d244b5
--- /dev/null
+++ b/src/fuzz/fuzz-journald-kmsg.c
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "fuzz.h"
+#include "journald-kmsg.h"
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+        Server s = {};
+        _cleanup_free_ char *buffer = NULL;
+
+        if (size == 0)
+                return 0;
+
+        s = (Server) {
+                .native_fd = -1,
+                .stdout_fd = -1,
+                .dev_kmsg_fd = -1,
+                .audit_fd = -1,
+                .hostname_fd = -1,
+                .notify_fd = -1,
+                .storage = STORAGE_NONE,
+        };
+        assert_se(sd_event_default(&s.event) >= 0);
+        buffer = memdup(data, size);
+        assert_se(buffer);
+        dev_kmsg_record(&s, buffer, size);
+        server_done(&s);
+
+        return 0;
+}
diff --git a/src/fuzz/meson.build b/src/fuzz/meson.build
index f1f1db2181..5fd3093f07 100644
--- a/src/fuzz/meson.build
+++ b/src/fuzz/meson.build
@@ -51,6 +51,11 @@ fuzzers += [
           libshared],
          [libmount]],
 
+        [['src/fuzz/fuzz-journald-kmsg.c'],
+         [libjournal_core,
+          libshared],
+         [libselinux]],
+
         [['src/fuzz/fuzz-journald-native.c',
           'src/fuzz/fuzz-journald.c'],
          [libjournal_core,
diff --git a/src/journal/journald-kmsg.c b/src/journal/journald-kmsg.c
index 9fe9231d80..ce82102eed 100644
--- a/src/journal/journald-kmsg.c
+++ b/src/journal/journald-kmsg.c
@@ -94,7 +94,7 @@ static bool is_us(const char *identifier, const char *pid) {
                streq(identifier, program_invocation_short_name);
 }
 
-static void dev_kmsg_record(Server *s, char *p, size_t l) {
+void dev_kmsg_record(Server *s, char *p, size_t l) {
 
         _cleanup_free_ char *message = NULL, *syslog_priority = NULL, *syslog_pid = NULL, *syslog_facility = NULL, *syslog_identifier = NULL, *source_time = NULL, *identifier = NULL, *pid = NULL;
         struct iovec iovec[N_IOVEC_META_FIELDS + 7 + N_IOVEC_KERNEL_FIELDS + 2 + N_IOVEC_UDEV_FIELDS];
@@ -235,7 +235,7 @@ static void dev_kmsg_record(Server *s, char *p, size_t l) {
                         j = 0;
                         FOREACH_DEVICE_DEVLINK(d, g) {
 
-                                if (j > N_IOVEC_UDEV_FIELDS)
+                                if (j >= N_IOVEC_UDEV_FIELDS)
                                         break;
 
                                 b = strappend("_UDEV_DEVLINK=", g);
diff --git a/src/journal/journald-kmsg.h b/src/journal/journald-kmsg.h
index bff24ac310..2326bc8c93 100644
--- a/src/journal/journald-kmsg.h
+++ b/src/journal/journald-kmsg.h
@@ -9,3 +9,5 @@ int server_flush_dev_kmsg(Server *s);
 void server_forward_kmsg(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred);
 
 int server_open_kernel_seqnum(Server *s);
+
+void dev_kmsg_record(Server *s, char *p, size_t l);