1 files changed, 54 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/timer_crash.c b/tools/testing/selftests/bpf/progs/timer_crash.c
new file mode 100644
index 000000000000..f8f7944e70da
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/timer_crash.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+struct map_elem {
+	struct bpf_timer timer;
+	struct bpf_spin_lock lock;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, int);
+	__type(value, struct map_elem);
+} amap SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1);
+	__type(key, int);
+	__type(value, struct map_elem);
+} hmap SEC(".maps");
+
+int pid = 0;
+int crash_map = 0; /* 0 for amap, 1 for hmap */
+
+SEC("fentry/do_nanosleep")
+int sys_enter(void *ctx)
+{
+	struct map_elem *e, value = {};
+	void *map = crash_map ? (void *)&hmap : (void *)&amap;
+
+	if (bpf_get_current_task_btf()->tgid != pid)
+		return 0;
+
+	*(void **)&value = (void *)0xdeadcaf3;
+
+	bpf_map_update_elem(map, &(int){0}, &value, 0);
+	/* For array map, doing bpf_map_update_elem will do a
+	 * check_and_free_timer_in_array, which will trigger the crash if timer
+	 * pointer was overwritten, for hmap we need to use bpf_timer_cancel.
+	 */
+	if (crash_map == 1) {
+		e = bpf_map_lookup_elem(map, &(int){0});
+		if (!e)
+			return 0;
+		bpf_timer_cancel(&e->timer);
+	}
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";