diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6fba6423cc10..c78f335fa981 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -640,10 +640,9 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 	int cls_id, totct = 0;
 	bool wanted;
 
-	cl_str = tmp = kstrdup(instr, GFP_KERNEL);
-	p = strchr(cl_str, '\n');
-	if (p)
-		*p = '\0';
+	cl_str = tmp = kstrdup_and_replace(instr, '\n', '\0', GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
 
 	/* start with previously set state-bits, then modify */
 	curr_bits = old_bits = *dcp->bits;