diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 728909f7951ca3e0299f4fb1c67c24f6026934c8..ed8601a1a861d40e51e33baa8ae47b8d5e33d630 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -494,7 +494,7 @@ static const struct bpf_func_proto bpf_probe_read_str_proto = {
 	.gpl_only	= true,
 	.ret_type	= RET_INTEGER,
 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
-	.arg2_type	= ARG_CONST_SIZE,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
 	.arg3_type	= ARG_ANYTHING,
 };